IIS 8.5 Site Security Technical Implementation Guide

V1R5 2018-09-18       U_MS_IIS_8-5_Site_STIG_V1R5_Manual-xccdf.xml
V1R8 2019-06-28       U_MS_IIS_8-5_Site_V1R8_Manual-xccdf.xml
This Security Technical Implementation Guide is published as a tool to improve the security of Department of Defense (DoD) information systems. The requirements are derived from the National Institute of Standards and Technology (NIST) 800-53 and related documents. Comments or proposed revisions to this document should be sent via email to the following address: [email protected]
Comparison
All 54
No Change 37
Updated 16
Added 1
Removed 0
V-76773 Added
Findings ID: IISW-SI-000200 Rule ID: SV-91469r1_rule Severity: medium CCI: CCI-000054

Discussion

Resource exhaustion can occur when an unlimited number of concurrent requests are allowed on a website, facilitating a Denial of Service attack. Mitigating this kind of attack will include limiting the number of concurrent HTTP/HTTPS requests per IP address and may include, where feasible, limiting parameter values associated with keepalive (i.e., a parameter used to limit the amount of time a connection may be inactive).

Checks

Access the IIS 8.5 IIS Manager. Click the IIS 8.5 server. Select "Configuration Editor" under the "Management" section. From the "Section:" drop-down list at the top of the configuration editor, locate "system.applicationHost/sites". Expand "siteDefaults". Expand "limits". Review the results and verify the value is greater than zero for the "maxconnections" parameter. If the maxconnections parameter is set to zero, this is a finding.

Fix

Access the IIS 8.5 IIS Manager. Click the IIS 8.5 server. Select "Configuration Editor" under the "Management" section. From the "Section:" drop-down list at the top of the configuration editor, locate "system.applicationHost/sites". Expand "siteDefaults". Expand "limits". Set the "maxconnections" parameter to a value greater than zero.
V-76775 No Change
Findings ID: IISW-SI-000201 Rule ID: SV-91471r1_rule Severity: medium CCI: CCI-000054

Discussion

When the session information is stored on the client, the session ID, along with the user authorization and identity information, is sent along with each client request and is stored in either a cookie, embedded in the uniform resource locator (URL), or placed in a hidden field on the displayed form. Each of these offers advantages and disadvantages. The biggest disadvantage to all three is the hijacking of a session along with all of the user's credentials.

When the user authorization and identity information is stored on the server in a protected and encrypted database, the communication between the client and web server will only send the session identifier, and the server can then retrieve user credentials for the session when needed. If, during transmission, the session were to be hijacked, the user's credentials would not be compromised.

ASP.NET provides a session state, which is available as the HttpSessionState class, as a method of storing session-specific information that is visible only within the session. ASP.NET session state identifies requests from the same browser during a limited time window as a session, and provides the ability to persist variable values for the duration of that session.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the "ASP.NET" section, select "Session State".

Under "Session State Mode Settings", verify the "In Process" mode is selected.

If the "Session State Mode Settings" is set to "In Process", this is not a finding.

Alternative method:

Click the site name.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.web/sessionState".

Verify the "mode" reflects "InProc".

If the "mode" is not set to "InProc", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the "ASP.NET" section, select "Session State".

Under "Session State Mode Settings", verify the "In Process" mode is selected.

Select "Apply" from the "Actions" pane.
V-76777 Updated
Findings ID: IISW-SI-000202 Rule ID: SV-91473r32_rule Severity: medium CCI: CCI-000054

Discussion

When the session information is stored on the client, the session ID, along with the user authorization and identity information, is sent along with each client request and is stored in either a cookie, embedded in the uniform resource locator (URL), or placed in a hidden field on the displayed form. Each of these offers advantages and disadvantages. The biggest disadvantage to all three is the hijacking of a session along with all of the user's credentials.

When the user authorization and identity information is stored on the server in a protected and encrypted database, the communication between the client and website will only send the session identifier, and the server can then retrieve user credentials for the session when needed. If, during transmission, the session were to be hijacked, the user's credentials would not be compromised.

ASP.NET provides a session state, which is available as the HttpSessionState class, as a method of storing session-specific information that is visible only within the session. ASP.NET session state identifies requests from the same browser during a limited time window as a session, and provides the ability to persist variable values for the duration of that session.

Cookies associate session information with client information for the duration of a user’s connection to a website. Using cookies is a more efficient way to track session state than any of the methods that do not use cookies because cookies do not require any redirection.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the "ASP.NET" section, select "Session State".

Under "Cookie Settings", verify the "Use Cookies" mode is selected from the "Mode:" drop-down list.

If the "Use Cookies" mode is selected, this is not a finding.

Alternative method:

Click the site name.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.web/sessionState".

Verify the "cookieless" is set to "UseCookies".

If the "cookieless" is not set to "UseCookies", this is a finding.
Note: If IIS 8.5 server/site is used only for system-to-system maintenance, does not allow users to connect to interface, and is restricted to specific system IPs, this is Not Applicable.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the ASP.NET section, select "Session State".

Under "Cookie Settings", select the "Use Cookies" from the "Mode:" drop-down list.

Select "Apply" from the "Actions" pane.
V-76779 Updated
Findings ID: IISW-SI-000203 Rule ID: SV-91475r31_rule Severity: medium CCI: CCI-000068

Discussion

Transport Layer Security (TLS) encryption is a required security setting for a private web server. Encryption of private information is essential to ensuring data confidentiality. If private information is not encrypted, it can be intercepted and easily read by an unauthorized party. A private web server must use a FIPS 140-2-approved TLS version, and all non-FIPS-approved SSL versions must be disabled.

FIPS 140-2-approved TLS versions include TLS V1.1 or greater. NIST SP 800-52 specifies the preferred configurations for government systems.

Checks

Note: If the server being reviewed is a public IIS 8.5 web server, this is Not Applicable.

Note: If SSL is installed on load balancer/proxy server through which traffic is routed to the IIS 8.5 server, and the IIS 8.5 server receives traffic from the load balancer/proxy server, the SSL requirement must be met on the load balancer/proxy server.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Double-click the "SSL Settings" icon.

Verify "Require SSL" check box is selected.

If the "Require SSL" check box is not selected, this is a finding.

Fix

Note: If the server being reviewed is a public IIS 8.5 web server, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Double-click the "SSL Settings" icon.

Select "Require SSL" check box.

Select "Apply" from the "Actions" pane.
V-76781 No Change
Findings ID: IISW-SI-000204 Rule ID: SV-91477r1_rule Severity: medium CCI: CCI-000068

Discussion

Transport Layer Security (TLS) encryption is a required security setting for a private web server. Encryption of private information is essential to ensuring data confidentiality. If private information is not encrypted, it can be intercepted and easily read by an unauthorized party. A private web server must use a FIPS 140-2-approved TLS version, and all non-FIPS-approved SSL versions must be disabled.

FIPS 140-2-approved TLS versions include TLS V1.1 or greater. NIST SP 800-52 specifies the preferred configurations for government systems.

Checks

Note: If the server being reviewed is a private IIS 8.5 web server, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Double-click the "SSL Settings" icon.

Verify "Require SSL" check box is selected.

If the "Require SSL" check box is not selected, this is a finding.

Fix

Note: If the server being reviewed is a private IIS 8.5 web server, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Double-click the "SSL Settings" icon.

Select "Require SSL" check box.

Select "Apply" from the "Actions" pane.
V-76783 No Change
Findings ID: IISW-SI-000205 Rule ID: SV-91479r1_rule Severity: medium CCI: CCI-001462

Discussion

Log files are a critical component to the successful management of an IS used within the DoD. By generating log files with useful information web administrators can leverage them in the event of a disaster, malicious attack, or other site-specific needs.

Ascertaining the correct order of the events that occurred is important during forensic analysis. Events that appear harmless by themselves might be flagged as a potential threat when properly viewed in sequence. By also establishing the event date and time, an event can be properly viewed with an enterprise tool to fully see a possible threat in its entirety.

Without sufficient information establishing when the log event occurred, investigation into the cause of event is severely hindered. Log record content that may be necessary to satisfy the requirement of this control includes, but is not limited to, time stamps, source and destination IP addresses, user/process identifiers, event descriptions, application-specific events, success/fail indications, file names involved, access control, or flow control rules invoked.

Satisfies: SRG-APP-000092-WSR-000055, SRG-APP-000093-WSR-000053

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Under Format select "W3C".

Click “Select Fields”, verify at a minimum the following fields are checked: Date, Time, Client IP Address, User Name, Method, URI Query, Protocol Status, and Referrer.

If the "W3C" is not selected as the logging format OR any of the required fields are not selected, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Under Format select "W3C".

Select the following fields: Date, Time, Client IP Address, User Name, Method, URI Query, Protocol Status, and Referrer.

Select "Apply" from the "Actions" pane.
V-76785 No Change
Findings ID: IISW-SI-000206 Rule ID: SV-91481r1_rule Severity: medium CCI: CCI-000139

Discussion

Internet Information Services (IIS) on Windows Server 2012 provides basic logging capabilities. However, because IIS takes some time to flush logs to disk, administrators do not have access to logging information in real-time. In addition, text-based log files can be difficult and time-consuming to process.

In IIS 8.5, the administrator has the option of sending logging information to Event Tracing for Windows (ETW). This option gives the administrator the ability to use standard query tools, or create custom tools, for viewing real-time logging information in ETW. This provides a significant advantage over parsing text-based log files that are not updated in real time.

Satisfies: SRG-APP-000092-WSR-000055, SRG-APP-000108-WSR-000166

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Under Log Event Destination, verify the "Both log file and ETW event" radio button is selected.

If the "Both log file and ETW event" radio button is not selected, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Under Log Event Destination, select the "Both log file and ETW event" radio button.

Select "Apply" from the "Actions" pane.
V-76787 Updated
Findings ID: IISW-SI-000208 Rule ID: SV-91483r32_rule Severity: medium CCI: CCI-000133

Discussion

Web server logging capability is critical for accurate forensic analysis. Without sufficient and accurate information, a correct replay of the events cannot be determined.

Ascertaining the correct source, e.g. source IP, of the events is important during forensic analysis. Correctly determining the source of events will add information to the overall reconstruction of the logable event. By determining the source of the event correctly, analysis of the enterprise can be undertaken to determine if events tied to the source occurred in other areas within the enterprise.

A web server behind a load balancer or proxy server, when not configured correctly, will record the load balancer or proxy server as the source of every logable event. When looking at the information forensically, this information is not helpful in the investigation of events. The web server must record with each event the client source of the event.

Checks

Interview the System Administrator to review the configuration of the IIS 8.5 architecture and determine if inbound web traffic is passed through a proxy.

If the IIS 8.5 is receiving inbound web traffic through a proxy, the audit logs must be reviewed to determine if correct source information is being passed through by the proxy server.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Click on "View log file" button.

When log file is displaced, review source IP information in log entries and verify entries do not reflect the IP address of the proxy server.

If the website is not behind a load balancer or proxy server, this is Not Applicable.

If the log entries in the log file(s) reflect the IP address of the proxy server as the source, this is a finding.

If provisions have been made to log the client IP via another field (i.e., utilizing X-Forwarded-For)the website is not behind a load balancer or proxy server, this is nNot a findingApplicable.

Fix

Access the proxy server through which inbound web traffic is passed and configure settings to pass web traffic to the IIS 8.5 web server transparently.
V-76789 Updated
Findings ID: IISW-SI-000209 Rule ID: SV-91485r21_rule Severity: medium CCI: CCI-000134

Discussion

Web server logging capability is critical for accurate forensic analysis. Without sufficient and accurate information, a correct replay of the events cannot be determined.

Ascertaining the success or failure of an event is important during forensic analysis. Correctly determining the outcome will add information to the overall reconstruction of the logable event. By determining the success or failure of the event correctly, analysis of the enterprise can be undertaken to determine if events tied to the event occurred in other areas within the enterprise.

Without sufficient information establishing the success or failure of the logged event, investigation into the cause of event is severely hindered. The success or failure also provides a means to measure the impact of an event and help authorized personnel to determine the appropriate response. Log record content that may be necessary to satisfy the requirement of this control includes, but is not limited to, time stamps, source and destination IP addresses, user/process identifiers, event descriptions, application-specific events, success/fail indications, file names involved, access control, or flow control rules invoked.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Select the website being reviewed.

Under "IIS", double-click the "Logging" icon.

Verify the "Format:" under "Log File" is configured to "W3C".

Select the "Fields" button.

Under "Custom Fields", verify the following fields are selected:

Request Header >> Connection

Request Header >> Warning

Server Variable >> HTTP_CONNECTION

If any of the above fields are not selected, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Select the website being reviewed.

Under "IIS", double-click the "Logging" icon.

Configure the "Format:" under "Log File" to "W3C".

Select the "Fields" button.

Under "Custom Fields", select the following fields:

Request Header >> Connection

Request Header >> Warning

Server Variable >> HTTP_CONNECTION

Click "OK".

Select "Apply" from the "Actions" pane.
V-76791 Updated
Findings ID: IISW-SI-000210 Rule ID: SV-91487r31_rule Severity: medium CCI: CCI-001487

Discussion

Web server logging capability is critical for accurate forensic analysis. Without sufficient and accurate information, a correct replay of the events cannot be determined.

Determining user accounts, processes running on behalf of the user, and running process identifiers also enable a better understanding of the overall event. User tool identification is also helpful to determine if events are related to overall user access or specific client tools.

Log record content that may be necessary to satisfy the requirement of this control includes: time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, file names involved, and access control or flow control rules invoked.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 web server IIS 8.5 Manager.

Under "IIS", double-click the "Logging" icon.

Verify the "Format:" under "Log File" is configured to "W3C".

Select the "Fields" button.

Under "Standard Fields", verify "User Agent", "User Name" and "Referrer" are selected.

Under "Custom Fields", verify the following fields have been configured:

Server Variable >> HTTP_USER_AGENT

Request Header >> User-Agent

Request Header >> Authorization

Response Header >> Content-Type

If any of the above fields are not selected, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 web server IIS 8.5 Manager.

Select the website being reviewed.

Under "IIS", double-click the "Logging" icon.

Configure the "Format:" under "Log File" to "W3C".

Select the "Fields" button.

Under "Standard Fields", select "User Agent", "User Name" and "Referrer".

Under "Custom Fields", select the following fields:

Server Variable >> HTTP_USER_AGENT

Request Header >> User-Agent

Request Header >> Authorization

Response Header >> Content-Type

Click "OK".

Select "Apply" from the "Actions" pane.
V-76795 Updated
Findings ID: IISW-SI-000213 Rule ID: SV-91491r42_rule Severity: medium CCI: CCI-000163

Discussion

A major tool in exploring the website use, attempted use, unusual conditions, and problems are the access and error logs. In the event of a security incident, these logs can provide the SA and the web manager with valuable information. Failure to protect log files could enable an attacker to modify the log file data or falsify events to mask an attacker's activity.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Click "Browse" and navigate to the directory where the log files are stored.

Right-click the log file name to review and click “Properties”.

Click the “Security” tab.
V
; verify only authorized groups are listed, if others are listed, this is a finding.

Note: The log file should be restricted as follows:
Auditors - Full Control
SYSTEM - Full Control
Administrators - Full Control
W

SYSTEM, Auditors group: Full
SA, w
eb Mmanagers -: Read

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Click the "Logging" icon.

Click "Browse" and navigate to the directory where the log files are stored.

Right-click the log file name to review and click “Properties”.

Click the “Security” tab.

Set the log file permissions for the appropriate group.
V-76797 No Change
Findings ID: IISW-SI-000214 Rule ID: SV-91493r1_rule Severity: medium CCI: CCI-000381

Discussion

Controlling what a user of a hosted application can access is part of the security posture of the web server. Any time a user can access more functionality than is needed for the operation of the hosted application poses a security issue. A user with too much access can view information that is not needed for the user's job role, or the user could use the function in an unintentional manner.

A MIME tells the web server what type of program various file types and extensions are and what external utilities or programs are needed to execute the file type.

A shell is a program that serves as the basic interface between the user and the operating system, so hosted application users must not have access to these programs. Shell programs may execute shell escapes and can then perform unauthorized activities that could damage the security posture of the web server.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the IIS 8.5 site.

Under IIS, double-click the “MIME Types” icon.

From the "Group by:" drop-down list, select "Content Type".

From the list of extensions under "Application", verify MIME types for OS shell program extensions have been removed, to include at a minimum, the following extensions:

.exe
.dll
.com
.bat
.csh

If any OS shell MIME types are configured, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the IIS 8.5 site.

Under IIS, double-click the “MIME Types” icon.

From the "Group by:" drop-down list, select "Content Type".

From the list of extensions under "Application", remove MIME types for OS shell program extensions, to include at a minimum, the following extensions:

.exe
.dll
.com
.bat
.csh

Select "Apply" from the "Actions" pane.
V-76799 Updated
Findings ID: IISW-SI-000215 Rule ID: SV-91495r21_rule Severity: medium CCI: CCI-000381

Discussion

IIS 8.5 will either allow or deny script execution based on file extension. The ability to control script execution is controlled through two features with IIS 8.5, Request Filtering and "Handler Mappings".

For "
Request FilterHandler Mappings", the ISSO must document and approve all allowable file extensions the website allows (white list) and denies (black list) by the website. The white list and black list will be compared to the "Request FilterHandler Mappings" in IIS 8. "Request FilterHandler Mappings" at the site level take precedence over "Request FilterHandler Mappings" at the server level.

Checks

For "Request FilterHandler Mappings", the ISSO must document and approve all allowable scripts the website allows (white list) and denies (black list) by the website. The white list and black list will be compared to the "Request FilterHandler Mappings" in IIS 8.5. "Request FilterHandler Mappings" at the site level take precedence over "Request FilterHandler Mappings" at the server level.

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click
Request Filtering->File Name Extensions Tab"Handler Mappings".

If any script file extensions from the black list are
not denienabled, this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click
Request Filtering->File Name Extensions Tab->Deny File Name Extension.

Add
"Handler Mappings".

Remove
any script file extensions listed on the black list that are not listenabled.

Select "Apply" from the "Actions" pane.
V-76801 No Change
Findings ID: IISW-SI-000216 Rule ID: SV-91497r1_rule Severity: medium CCI: CCI-000381

Discussion

Resource mapping is the process of tying a particular file type to a process in the web server that can serve that type of file to a requesting client and to identify which file types are not to be delivered to a client.

By not specifying which files can and which files cannot be served to a user, the web server could deliver to a user web server configuration files, log files, password files, etc.

The web server must only allow hosted application file types to be served to a user and all other types must be disabled.

Checks

For "Handler Mappings", the ISSO must document and approve all allowable file extensions the website allows (white list) and denies (black list) by the website. The white list and black list will be compared to the "Handler Mappings" in IIS 8.5. "Handler Mappings" at the site level take precedence over "Handler Mappings" at the server level.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click "Request Filtering".

If any file name extensions from the black list have "Allowed" set to "True", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click "Request Filtering".

For any file name extensions from the black list which have "Allowed" set to "True", remove the file name extension.

Select "Deny File Name Extension" from the "Actions" pane.

Add each file name extension from the black list.

Select "Apply" from the "Actions" pane.
V-76803 No Change
Findings ID: IISW-SI-000217 Rule ID: SV-91499r1_rule Severity: medium CCI: CCI-000381

Discussion

A web server can be installed with functionality that, just by its nature, is not secure. Web Distributed Authoring (WebDAV) is an extension to the HTTP protocol that, when developed, was meant to allow users to create, change, and move documents on a server, typically a web server or web share. Allowing this functionality, development, and deployment is much easier for web authors.

WebDAV is not widely used and has serious security concerns because it may allow clients to modify unauthorized files on the web server.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Select the IIS 8.5 website.

Review the features listed under the "IIS" section.

If the "WebDAV Authoring Rules" icon exists, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access Server Manager on the IIS 8.5 website.

Select the Local Server.

Click on "Manage".

Select "Add Roles and Features".

Click "Next" on the "Before you begin" dialog box.

Select "Role-based or feature-based installation" on the "Installation Type" dialog box and click on "Next".

Select the IIS 8.5 web server on the "Server Selection" dialog box.

From the "Windows Features" dialog box, navigate to "World Wide Web Services" >> "Common HTTP Features".

De-select "WebDAV Publishing" and click "Next" to complete removing the WebDAV Publishing feature from the IIS 8.5 web server.

Select "Apply" from the "Actions" pane.
V-76805 No Change
Findings ID: IISW-SI-000218 Rule ID: SV-91501r2_rule Severity: medium CCI: CCI-000381

Discussion

A web server may host too many applications. Each application will need certain system resources and privileged operations to operate correctly. An application's trust level determines the permissions granted by the ASP.NET Code Access Security (CAS) policy. An application with full trust permissions may access all resource types on a server and perform privileged operations, while applications running with partial trust have varying levels of operating permissions and access to resources. The CAS determines the permissions granted to the application on the server. Setting a level of trust compatible with the applications will limit the potential harm a compromised application could cause to a system. The web server must be configured to contain and control the applications and protect the system resources and privileged operations from those not needed by the application for operation.

Limiting the application will confine the potential harm a compromised application could cause to a system.

Checks

Note: If the server being reviewed is a non-production website, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the ".NET Trust Level" icon.

If the ".NET Trust Level" is not set to Full or less, this is a finding.

Fix

Note: If the server being reviewed is a non-production website, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the ".NET Trust Level" icon.

Set the ".NET Trust Level" to Full or less and click “Apply”.

Select "Apply" from the "Actions" pane.
V-76807 Updated
Findings ID: IISW-SI-000219 Rule ID: SV-91503r21_rule Severity: medium CCI: CCI-000382

Discussion

The web server must be configured to listen on a specified IP address and port. Without specifying an IP address and port for the web server to utilize, the web server will listen on all IP addresses available to the hosting server. If the web server has multiple IP addresses, i.e., a management IP address, the web server will also accept connections on the management IP address.

Accessing the hosted application through an IP address normally used for non-application functions opens the possibility of user access to resources, utilities, files, ports, and protocols that are protected on the desired application IP address.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Right-click on the site name under review.

Select “Edit Bindings”.

Verify there are hostname entries and unique IP addresses assigned to port 80 for HTTP and port 443 for HTTPS.
Other approved and documented ports may be used.

If both hostname entries and unique IP addresses are not configure to port 80 for HTTP and port 443 for HTTPS
(or other approved and documented port), this is a finding.

Note: If certificate handling is performed at the Proxy/Load Balancer
, this is not a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Right-click on the site name under review.

Select “Edit Bindings”.

Assign hostname entries and unique IP addresses to port 80 for HTTP and port 443 for HTTPS.
Other approved and documented ports may be used.

Click "OK".

Select "Apply" from the "Actions" pane.
V-76809 No Change
Findings ID: IISW-SI-000220 Rule ID: SV-91505r1_rule Severity: medium CCI: CCI-000197

Discussion

A DoD private website must utilize PKI as an authentication mechanism for web users. Information systems residing behind web servers requiring authorization based on individual identity must use the identity provided by certificate-based authentication to support access control decisions. Not using client certificates allows an attacker unauthenticated access to private websites.

Satisfies: SRG-APP-000172-WSR-000104, SRG-APP-000224-WSR-000135, SRG-APP-000427-WSR-000186

Checks

Note: If the server being reviewed is a public IIS 8.5 web server, this is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click the "SSL Settings" icon.

Verify the "Clients Certificate Required" check box is selected.

If the "Clients Certificate Required" check box is not selected, this is a finding.

Fix

Note: If the server being reviewed is a public IIS 8.5 web server, this is Not Applicable

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click the "SSL Settings" icon.

Verify the "Clients Certificate Required" check box is selected.

Select "Apply" from the "Actions" pane.
V-76811 No Change
Findings ID: IISW-SI-000221 Rule ID: SV-91507r2_rule Severity: high CCI: CCI-001082

Discussion

Many of the security problems that occur are not the result of a user gaining access to files or data for which the user does not have permissions, but rather users are assigned incorrect permissions to unauthorized data. The files, directories, and data that are stored on the web server need to be evaluated and a determination made concerning authorized access to information and programs on the server. Only authorized users and administrative accounts will be allowed on the host server in order to maintain the web server, applications, and review the server operations.

Checks

Check the account used for anonymous access to the website.

Follow the procedures below for each site hosted on the IIS 8.5 web server:
Open the IIS 8.5 Manager.

Double-click "Authentication" in the IIS section of the website’s Home Pane.

If Anonymous access is disabled, this is Not a Finding.

If Anonymous access is enabled, click “Anonymous Authentication”.

Click “Edit” in the "Actions" pane.

If the “Specific user” radio button is enabled and an ID is specified in the adjacent control box, this is the ID being used for anonymous access. Note: account name.

Check privileged groups that may allow the anonymous account inappropriate membership:
Open “Server Manager” on the machine.

Expand Configuration.

Expand Local Users and Groups.

Click “Groups”.

Review members of any of the following privileged groups:

Administrators
Backup Operators
Certificate Services (of any designation)
Distributed COM Users
Event Log Readers
Network Configuration Operators
Performance Log Users
Performance Monitor Users
Power Users
Print Operators
Remote Desktop Users
Replicator
Users

Double-click each group and review its members.

If the IUSR account or any account noted above used for anonymous access is a member of any group with privileged access, this is a finding.

Fix

Remove the Anonymous access account from all privileged accounts and all privileged groups.
V-76813 No Change
Findings ID: IISW-SI-000223 Rule ID: SV-91509r1_rule Severity: medium CCI: CCI-001188

Discussion

Communication between a client and the web server is done using the HTTP protocol, but HTTP is a stateless protocol. In order to maintain a connection or session, a web server will generate a session identifier (ID) for each client session when the session is initiated. The session ID allows the web server to track a user session and, in many cases, the user, if the user previously logged into a hosted application.

By being able to guess session IDs, an attacker can easily perform a man-in-the-middle attack. To truly generate random session identifiers that cannot be reproduced, the web server session ID generator, when used twice with the same input criteria, must generate an unrelated random ID.

The session ID generator also needs to be a FIPS 140-2-approved generator.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the "ASP.NET" section, select "Session State".

Under "Session State" Mode Settings, verify the "In Process" mode is selected.

If the "In Process" mode is selected, this is not a finding.

Alternative method:

Click the site name.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.web/sessionState".

Verify the "mode" reflects "InProc".

If the "mode" is not set to "InProc", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Under the ASP.NET section, select "Session State".

Under "Session State" Mode Settings, select the "In Process" mode.
V-76815 No Change
Findings ID: IISW-SI-000224 Rule ID: SV-91511r1_rule Severity: medium CCI: CCI-001084

Discussion

The web document (home) directory is accessed by multiple anonymous users when the web server is in production. By locating the web document (home) directory on the same partition as the web server system file the risk for unauthorized access to these protected files is increased. Additionally, having the web document (home) directory path on the same drive as the system folders also increases the potential for a drive space exhaustion attack.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Click the "Advanced Settings" from the "Actions" pane.

Review the Physical Path.

If the Path is on the same partition as the OS, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Click the “Advanced Settings” from the "Actions" pane.

Change the Physical Path to the new partition and directory location.
V-76817 No Change
Findings ID: IISW-SI-000225 Rule ID: SV-91513r1_rule Severity: medium CCI: CCI-001094

Discussion

Request filtering replaces URLScan in IIS, enabling administrators to create a more granular rule set with which to allow or reject inbound web content. By setting limits on web requests, it helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The MaxURL Request Filter limits the number of bytes the server will accept in a URL.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If the "maxUrl" value is not set to "4096" or less, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Set the "maxURL" value to "4096" or less.
V-76819 No Change
Findings ID: IISW-SI-000226 Rule ID: SV-91515r2_rule Severity: medium CCI: CCI-001094

Discussion

By setting limits on web requests, it ensures availability of web services and mitigates the risk of buffer overflow type attacks. The maxAllowedContentLength Request Filter limits the number of bytes the server will accept in a request.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If the "maxAllowedContentLength" value is not explicitly set to "30000000" or less or a length documented and approved by the ISSO, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Set the "maxAllowedContentLength" value to "30000000" or less.
V-76821 No Change
Findings ID: IISW-SI-000227 Rule ID: SV-91517r1_rule Severity: medium CCI: CCI-001094

Discussion

By setting limits on web requests, it helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The Maximum Query String Request Filter describes the upper limit on allowable query string lengths. Upon exceeding the configured value, IIS will generate a Status Code 404.15.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If the "Maximum Query String" value is not set to "2048" or less, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Set the "Maximum Query String" value to "2048" or less.
V-76823 No Change
Findings ID: IISW-SI-000228 Rule ID: SV-91519r1_rule Severity: medium CCI: CCI-001094

Discussion

By setting limits on web requests, it ensures availability of web services and mitigates the risk of buffer overflow type attacks. The allow high-bit characters Request Filter enables rejection of requests containing non-ASCII characters.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If the "Allow high-bit characters" check box is checked, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Uncheck the "Allow high-bit characters" check box.
V-76825 No Change
Findings ID: IISW-SI-000229 Rule ID: SV-91521r1_rule Severity: medium CCI: CCI-001094

Discussion

Request filtering enables administrators to create a more granular rule set with which to allow or reject inbound web content. By setting limits on web requests, it ensures availability of web services and mitigates the risk of buffer overflow type attacks. When the “Allow double escaping” option is disabled it prevents attacks that rely on double-encoded requests.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If the "Allow double escaping" check box is checked, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Uncheck the "Allow double escaping" check box.
V-76827 No Change
Findings ID: IISW-SI-000230 Rule ID: SV-91523r2_rule Severity: medium CCI: CCI-001094

Discussion

Request filtering enables administrators to create a more granular rule set to allow or reject inbound web content. By setting limits on web requests it helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The allow unlisted property of the “File Extensions Request” filter enables rejection of requests containing specific file extensions not defined in the “File Extensions” filter. Tripping this filter will cause IIS to generate a Status Code 404.7.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click on the site name.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

If "Allow unlisted file name extensions" check box is checked, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Request Filtering" icon.

Click “Edit Feature Settings” in the "Actions" pane.

Uncheck the "Allow unlisted file extensions" check box.
V-76829 No Change
Findings ID: IISW-SI-000231 Rule ID: SV-91525r1_rule Severity: medium CCI: CCI-001310

Discussion

Directory browsing allows the contents of a directory to be displayed upon request from a web client. If directory browsing is enabled for a directory in IIS, users could receive a web page listing the contents of the directory. If directory browsing is enabled the risk of inadvertently disclosing sensitive content is increased.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Click the Site.

Double-click the "Directory Browsing" icon.

If the "Directory Browsing" is not installed, this is Not Applicable.

Under the "Actions" pane verify "Directory Browsing" is "Disabled".

If "Directory Browsing" is not "Disabled", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the Site.

Double-click the "Directory Browsing" icon.

Under the "Actions" pane click "Disabled".
V-76831 No Change
Findings ID: IISW-SI-000232 Rule ID: SV-91527r1_rule Severity: medium CCI: CCI-001312

Discussion

The goal is to control the web users experience in navigating any portion of the web document root directories. Ensuring all web content directories have at least the equivalent of an index.html file is a significant factor to accomplish this end. Also, enumeration techniques, such as URL parameter manipulation, rely upon being able to obtain information about the web server’s directory structure by locating directories with default pages. This practice helps ensure the anonymous web user will not obtain directory browsing information or an error message revealing the server type and version.

Checks

Note: This requirement is only for each site's root directory.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Click the site name under review.

Double-click "Default Document".

In the "Actions" pane, verify the "Default Document" feature is enabled.

If an "Enable" option is listed under the "Actions" pane, the "Default Document" feature is not enabled and this is a finding.

If "Default Document" is "Enabled, review the document types.

Click the "Content View" tab, click on each listed "Default Document" and click on "Explore" under the "Actions" pane. Verify there is a document of that type in the directory.

If "Default Document" is "Enabled" but no listed document types are present in the "Content View", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click "Default Document".

In the “Actions” pane select "Enable".

Click the "Content View" tab, click on each listed "Default Document" and click on "Explore" under the "Actions" pane. Create a valid document for the listed "Default Document".
V-76835 No Change
Findings ID: IISW-SI-000233 Rule ID: SV-91531r1_rule Severity: medium CCI: CCI-001312

Discussion

HTTP error pages contain information that could enable an attacker to gain access to an information system. Failure to prevent the sending of HTTP error pages with full information to remote requesters exposes internal configuration information to potential attackers.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Error Pages" icon.

Click each error message and click "Edit Feature" setting from the "Actions" pane.

If any error message is not set to “Detailed errors for local requests and custom error pages for remote requests”, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click the "Error Pages" icon.

Click each error message and click "Edit Feature" Setting from the "Actions" pane; set each error message to “Detailed errors for local requests and custom error pages for remote requests”.
V-76837 No Change
Findings ID: IISW-SI-000234 Rule ID: SV-91533r1_rule Severity: medium CCI: CCI-001312

Discussion

Setting compilation debug to false ensures detailed error information does not inadvertently display during live application usage, mitigating the risk of application information being displayed to users.

Checks

Note: If the ".NET feature" is not installed, this check is Not Applicable.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click ".NET Compilation".

Scroll down to the "Behavior" section and verify the value for "Debug" is set to "False".

If the "Debug" value is not set to "False", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click ".NET Compilation".

Scroll down to the "Behavior" section and set the value for "Debug" to "False".
V-76839 No Change
Findings ID: IISW-SI-000235 Rule ID: SV-91535r1_rule Severity: medium CCI: CCI-002361

Discussion

The idle time-out attribute controls the amount of time a worker process will remain idle before it shuts down. A worker process is idle if it is not processing requests and no new requests are received.

The purpose of this attribute is to conserve system resources; the default value for idle time-out is 20 minutes.

By default, the World Wide Web (WWW) service establishes an overlapped recycle, in which the worker process to be shut down is kept running until after a new worker process is started.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the Application Pools.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Process Model" section and verify the value for "Idle Time-out" is set to "20".

If the "Idle Time-out" is not set to "20" or less, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the Application Pools.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Process Model" section and set the value for "Idle Time-out" to "20" or less.
V-76841 No Change
Findings ID: IISW-SI-000236 Rule ID: SV-91537r2_rule Severity: medium CCI: CCI-002361

Discussion

Leaving sessions open indefinitely is a major security risk. An attacker can easily use an already authenticated session to access the hosted application as the previously authenticated user. By closing sessions after a set period of inactivity, the web server can make certain that those sessions that are not closed through the user logging out of an application are eventually closed.

Acceptable values are 5 minutes for high-value applications, 10 minutes for medium-value applications, and 20 minutes for low-value applications.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.web/sessionState".

Verify the "timeout" is set to "00:20:00 or less”, using the lowest value possible depending upon the application.
Acceptable values are 5 minutes for high-value applications, 10 minutes for medium-value applications, and 20 minutes for low-value applications.

If "timeout" is not set to "00:20:00 or less”, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.web/sessionState".

Set the "timeout" to "00:20:00 or less”, using the lowest value possible depending upon the application.
Acceptable values are 5 minutes for high-value applications, 10 minutes for medium-value applications, and 20 minutes for low-value applications.

In the "Actions" pane, click "Apply".
V-76843 No Change
Findings ID: IISW-SI-000237 Rule ID: SV-91539r1_rule Severity: medium CCI: CCI-002322

Discussion

During an attack on the web server or any of the hosted applications, the system administrator may need to disconnect or disable access by users to stop the attack.

The web server must provide a capability to disconnect users to a hosted application without compromising other hosted applications unless deemed necessary to stop the attack. Methods to disconnect or disable connections are to stop the application service for a specified hosted application, stop the web server, or block all connections through web server access list.

The web server capabilities used to disconnect or disable users from connecting to hosted applications and the web server must be documented to make certain that, during an attack, the proper action is taken to conserve connectivity to any other hosted application if possible and to make certain log data is conserved for later forensic analysis.

Checks

Interview the System Administrator and Web Manager.

Ask for documentation for the IIS 8.5 web server administration.

Verify there are documented procedures for shutting down an IIS 8.5 website in the event of an attack. The procedure should, at a minimum, provide the following steps:

Determine the respective website for the application at risk of an attack.

Access the IIS 8.5 web server IIS 8.5 Manager.

Select the respective website.

In the "Actions" pane, under "Manage Website", click on "Stop".

If necessary, stop all websites.

If necessary, stop the IIS 8.5 web server by selecting the web server in the IIS 8.5 Manager.

In the "Actions" pane, under "Manage Server", click on "Stop".

If there are not documented procedures with, at a minimum, the mentioned steps for stopping a website, this is a finding.

Fix

Prepare documented procedures for shutting down an IIS 8.5 website in the event of an attack. The procedure should, at a minimum, provide the following steps:

Determine the respective website for the application at risk of an attack.

Access the IIS 8.5 web server IIS 8.5 Manager.

Select the respective website.

In the "Actions" pane, under "Manage Website", click on "Stop".

If necessary, stop all websites.

If necessary, stop the IIS 8.5 web server by selecting the web server in the IIS 8.5 Manager.

In the "Actions" pane, under "Manage Server", click on "Stop".
V-76845 No Change
Findings ID: IISW-SI-000238 Rule ID: SV-91541r1_rule Severity: medium CCI: CCI-001849

Discussion

In order to make certain that the logging mechanism used by the web server has sufficient storage capacity in which to write the logs, the logging mechanism needs to be able to allocate log record storage capacity.

The task of allocating log record storage capacity is usually performed during initial installation of the logging mechanism. The system administrator will usually coordinate the allocation of physical drive space with the web server administrator along with the physical location of the partition and disk. Refer to NIST SP 800-92 for specific requirements on log rotation and storage dependent on the impact of the web server.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 web server IIS 8.5 Manager.

Under "IIS" double-click on the "Logging" icon.

In the "Logging" configuration box, determine the "Directory:" to which the "W3C" logging is being written.

Confirm with the System Administrator that the designated log path is of sufficient size to maintain the logging.

Under "Log File Rollover", verify the "Do not create new log files" is not selected.

Verify a schedule is configured to rollover log files on a regular basis.

Consult with the System Administrator to determine if there is a documented process for moving the log files off of the IIS 8.5 web server to another logging device.

If the designated logging path device is not of sufficient space to maintain all log files and there is not a schedule to rollover files on a regular basis, this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Under "IIS" double-click on the "Logging" icon.

If necessary, in the "Logging" configuration box, redesignate a log path to a location able to house the logs.

Under "Log File Rollover", deselect the "Do not create new log files" setting.

Configure a schedule to rollover log files on a regular basis.
V-76847 No Change
Findings ID: IISW-SI-000239 Rule ID: SV-91543r1_rule Severity: medium CCI: CCI-001762

Discussion

Web servers provide numerous processes, features, and functionalities that utilize TCP/IP ports. Some of these processes may be deemed unnecessary or too unsecure to run on a production system.

The web server must provide the capability to disable or deactivate network-related services that are deemed to be non-essential to the server mission, are too unsecure, or are prohibited by the PPSM CAL and vulnerability assessments.

Failure to comply with DoD ports, protocols, and services (PPS) requirements can result in compromise of enclave boundary protections and/or functionality of the AIS.

The ISSM will ensure web servers are configured to use only authorized PPS in accordance with the Network Infrastructure STIG, DoD Instruction 8551.1, Ports, Protocols, and Services Management (PPSM), and the associated Ports, Protocols, and Services (PPS) Assurance Category Assignments List.

Checks

Review the website to determine if HTTP and HTTPs (e.g., 80 and 443) are used in accordance with those ports and services registered and approved for use by the DoD PPSM. Any variation in PPS will be documented, registered, and approved by the PPSM.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

In the “Action” Pane, click “Bindings”.

Review the ports and protocols. If unknown ports or protocols are used, then this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

In the “Action” Pane, click “Bindings".

Edit to change an existing binding and set the correct ports and protocol.
V-76849 Updated
Findings ID: IISW-SI-000241 Rule ID: SV-91545r32_rule Severity: medium CCI: CCI-002470

Discussion

The use of a DoD PKI certificate ensures clients the private website they are connecting to is legitimate, and is an essential part of the DoD defense-in-depth strategy.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the site name under review.

Click “Bindings” in the “Action” Pane.

Click the “HTTPS type” from the box.

Click “Edit”.

Click “View” and then review and verify the certificate path.

If the list of CAs in the trust hierarchy does not lead to the DoD PKI Root CA, DoD-approved external certificate authority (ECA), or DoD-approved external partner, this is a finding.

If HTTPS is not an available type under site bindings, this is a finding.


If HTTPS is not an available type under site bindings, and the Web Server ONLY communicates directly with a load balancer/proxy server, with IP address and Domain Restrictions in place, this is not a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Click the Server name.

Double-click “Server Certificates”.

Click “Import” under the "Actions" pane.

Browse to the DoD certificate location, select it, and click “OK”.

Remove any non-DoD certificates if present.

Click on the site needing the certificate.

Select “Bindings” under the "Actions" pane.

Click on the binding needing a certificate and select “Edit”, or add a site binding for HTTPS.

Assign the certificate to the website by choosing it under the “SSL Certificate” drop-down and clicking “OK”.
V-76851 Updated
Findings ID: IISW-SI-000242 Rule ID: SV-91547r53_rule Severity: medium CCI: CCI-002476

Discussion

When data is written to digital media, such as hard drives, mobile computers, external/removable hard drives, personal digital assistants, flash/thumb drives, etc., there is risk of data loss and data compromise. User identities and passwords stored on the hard drive of the hosting hardware must be encrypted to protect the data from easily being discovered and used by an unauthorized user to access the hosted applications. The cryptographic libraries and functionality used to store and retrieve the user identifiers and passwords must be part of the web server.

Preventing the disclosure of transmitted information requires that the web server take measures to employ some form of cryptographic mechanism in order to protect the information during transmission. This is usually achieved through the use of Transport Layer Security (TLS).

Transmission of data can take place between the web server and a large number of devices/applications external to the web server. Examples are a web client used by a user, a backend database, an audit server, or other web servers in a web cluster.

If data is transmitted unencrypted, the data then becomes vulnerable to disclosure. The disclosure may reveal user identifier/password combinations, website code revealing business logic, or other user personal information.

Also satisfies: SRG-APP-000439-WSR-000151

Checks

Note: If SSL is installed on load balancer/proxy server through which traffic is routed to the IIS 8.5 server, and the IIS 8.5 server receives traffic from the load balancer/proxy server, the SSL requirement must be met on the load balancer/proxy server.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Verify "Require SSL" is checked.

Verify "Client Certificates Required" is selected.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate “system.webServer/security/access”.

The value for "sslFlags" set must include "ssl128".

If the "Require SSL" is not selected, this is a finding.

If the "Client Certificates Required" is not selected, this is a finding.

If the "sslFlags" is not set to "ssl128", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Select the "Require SSL" setting.

Select the "Client Certificates Required" setting.

Click "Apply" in the "Actions" pane.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate “system.webServer/security/access”.

Click on the drop-down list for "sslFlags".

Select the "Ssl128" check box.

Click "Apply" in the "Actions" pane.
V-76855 No Change
Findings ID: IISW-SI-000244 Rule ID: SV-91551r1_rule Severity: medium CCI: CCI-002418

Discussion

The HTTP protocol is a stateless protocol. To maintain a session, a session identifier is used. The session identifier is a piece of data that is used to identify a session and a user. If the session identifier is compromised by an attacker, the session can be hijacked. By encrypting the session identifier, the identifier becomes more difficult for an attacker to hijack, decrypt, and use before the session has expired.

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 Manager.

Select the website being reviewed.

Under "Management" section, double-click the "Configuration Editor" icon.

From the "Section:" drop-down list, select “system.webServer/asp".

Expand the "session" section.

Verify the "keepSessionIdSecure" is set to "True".

If the "keepSessionIdSecure" is not set to "True", this is a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 Manager.

Select the website being reviewed.

Under "Management" section, double-click the "Configuration Editor" icon.

From the "Section:" drop-down list, select “system.webServer/asp".

Expand the "session" section.

Select "True" for the "keepSessionIdSecure" setting.

Select "Apply" from the "Actions" pane.
V-76859 No Change
Findings ID: IISW-SI-000246 Rule ID: SV-91555r2_rule Severity: medium CCI: CCI-002418

Discussion

A cookie is used when a web server needs to share data with the client's browser. The data is often used to remember the client when the client returns to the hosted application at a later date. A session cookie is a special type of cookie used to remember the client during the session. The cookie will contain the session identifier (ID) and may contain authentication data to the hosted application. To protect this data from easily being compromised, the cookie must be encrypted.

When a cookie is sent encrypted via SSL/TLS, an attacker must spend a great deal of time and resources to decrypt the cookie. If, along with encryption, the cookie is compressed, the attacker can now use a combination of plaintext injection and inadvertent information leakage through data compression to reduce the time needed to decrypt the cookie. This attack is called Compression Ratio Info-leak Made Easy (CRIME).

Cookies shared between the web server and the client when encrypted should not also be compressed.

A cookie can be read by client-side scripts easily if cookie properties are not set properly. By allowing cookies to be read by the client-side scripts, information such as session identifiers could be compromised and used by an attacker who intercepts the cookie. Setting cookie properties (i.e. HttpOnly property) to disallow client-side scripts from reading cookies better protects the information inside the cookie.



Satisfies: SRG-APP-000439-WSR-000154, SRG-APP-000439-SSR-000155, SRG-APP-000439-WSR-000153

Checks

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 Manager.

Under "Management" section, double-click the "Configuration Editor" icon.

From the "Section:" drop-down list, select "system.web/httpCookies".

Verify the "require SSL" is set to "True".

From the "Section:" drop-down list, select "system.web/sessionState".

Verify the "compressionEnabled" is set to "False".

If both the "system.web/httpCookies:require SSL" is set to "True" and the "system.web/sessionState:compressionEnabled" is set to "False", this is not a finding.

Fix

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Access the IIS 8.5 Manager.

Under "Management" section, double-click the "Configuration Editor" icon.

From the "Section:" drop-down list, select "system.web/httpCookies".

Set the "require SSL" to "True".

From the "Section:" drop-down list, select "system.web/sessionState".

Set the "compressionEnabled" to "False".

Select "Apply" from the "Actions" pane.
V-76861 Updated
Findings ID: IISW-SI-000249 Rule ID: SV-91557r42_rule Severity: medium CCI: CCI-002420

Discussion

Information can be either unintentionally or maliciously disclosed or modified during preparation for transmission, including, for example, during aggregation, at protocol transformation points, and during packing/unpacking. These unauthorized disclosures or modifications compromise the confidentiality or integrity of the information.

An example of this would be an SMTP queue. This queue may be added to a web server through an SMTP module to enhance error reporting or to allow developers to add SMTP functionality to their applications.

Any modules used by the web server that queue data before transmission must maintain the confidentiality and integrity of the information before the data is transmitted.

Information can be either unintentionally or maliciously disclosed or modified during reception, including, for example, during aggregation, at protocol transformation points, and during packing/unpacking. These unauthorized disclosures or modifications compromise the confidentiality or integrity of the information.

Protecting the confidentiality and integrity of received information requires that application servers take measures to employ approved cryptography in order to protect the information during transmission over the network. This is usually achieved through the use of Transport Layer Security (TLS), SSL VPN, or IPsec tunnel.

The web server must utilize approved encryption when receiving transmitted data.

Also satisfies: SRG-APP-000442-WSR-000182

Checks

Note: If the server being reviewed is a public IIS 8.5 web server, this is Not Applicable.

Note: If SSL is installed on load balancer/proxy server through which traffic is routed to the IIS 8.5 server, and the IIS 8.5 server receives traffic from the load balancer/proxy server, the SSL requirement must be met on the load balancer/proxy server.

Follow the procedures below for each site hosted on the IIS 8.5 web server:

Open the IIS 8.5 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Verify "Require SSL" is checked.

Verify "Client Certificates Required" is selected.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate “system.webServer/security/access”.

The value for "sslFlags" should be ssl128.

If the "Require SSL" is not selected, this is a finding.

If the "Client Certificates Required" is not selected, this is a finding.

If the "sslFlags" is not set to "ssl128", this is a finding.

Fix

Follow the procedures below for web server and each site under review:

Open the IIS 8.5 Manager.

Click the site name.

Double-click the "SSL Settings" icon.

Select "Require SSL".
Select "Client Certificates Required".
Select “sslFlags”, and set to “s
check bex.
V-76865 Updated
Findings ID: IISW-SI-000251 Rule ID: SV-91561r32_rule Severity: medium CCI: CCI-000366

Discussion

Application pools isolate sites and applications to address reliability, availability, and security issues. Sites and applications may be grouped according to configurations, although each site will be associated with a unique application pool.

Checks

Note: If the IIS Application Pool is hosting Microsoft SharePoint, this is Not Applicable.

Open the IIS 8.5 Manager.

Click "Application Pools".

In the list of Application Pools, review the "Applications" column and verify unique application pools for each website.

If any Application Pools are being used for more than one website, this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the site name under review.

Assign a unique application pool to each website.
V-76867 Updated
Findings ID: IISW-SI-000252 Rule ID: SV-91563r32_rule Severity: medium CCI: CCI-000366

Discussion

IIS application pools can be periodically recycled to avoid unstable states possibly leading to application crashes, hangs, or memory leaks. By default, application pool recycling is overlapped, which means the worker process to be shut down is kept running until after a new worker process is started. After a new worker process starts, new requests are passed to it. The old worker process shuts down after it finishes processing its existing requests, or after a configured time-out, whichever comes first. This way of recycling ensures uninterrupted service to clients.

Checks

Note: Recycling Application Pools can create an unstable environment in a 64-bit SharePoint environment. If operational issues arise, with supporting documentation from the ISSO, this check can be downgraded to a Cat III.

Note: If the IIS Application Pool is hosting Microsoft SharePoint, this is Not Applicable.

Open the IIS 8.5 Manager.

Perform for each Application Pool.

Click the “Application Pools”.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling section" and verify the value for "Request Limit" is set to a value other than "0".

If the "Request Limit" is set to a value of "0", this is a finding.

Fix

Open the IIS 8.5 Manager.

Click on the “Application Pools”.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling section" and set the value for "Request Limit" to greater than "0".

Click “OK”.
V-76869 Updated
Findings ID: IISW-SI-000253 Rule ID: SV-91565r32_rule Severity: medium CCI: CCI-000366

Discussion

IIS application pools can be periodically recycled to avoid unstable states possibly leading to application crashes, hangs, or memory leaks. By default, application pool recycling is overlapped, which means the worker process to be shut down is kept running until after a new worker process is started. After a new worker process starts, new requests are passed to it. The old worker process shuts down after it finishes processing its existing requests, or after a configured time-out, whichever comes first. This way of recycling ensures uninterrupted service to clients.

Checks

Note: Recycling Application Pools can create an unstable environment in a 64-bit SharePoint environment. If operational issues arise, mitigation steps can be set, to include setting the “Fixed number or requests”, “Specific time”, and “Private memory usage” in the recycling conditions lieu of the “Virtual memory” setting. If mitigation is used in lieu of this requirement, with supporting documentation from the ISSO, this check can be downgraded to a Cat III.

Note: If the IIS Application Pool is hosting Microsoft SharePoint, this is Not Applicable.


Open the IIS 8.5 Manager.

Perform for each Application Pool.

Click on “Application Pools”.

Highlight an Application Pool and click "Advanced Settings" in the Action Pane.

In the "Advanced Settings" dialog box scroll down to the "Recycling" section and verify the value for "Virtual Memory Limit" is not set to 0.

If the value for "Virtual Memory Limit" is set to 0, this is a finding.

Fix

Open the IIS 8.5 Manager.

Click on “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

In the "Advanced Settings" dialog box scroll down to the "Recycling" section and set the value for "Virtual Memory Limit" to a value other than "0".

Click “OK”.
V-76871 Updated
Findings ID: IISW-SI-000254 Rule ID: SV-91567r21_rule Severity: medium CCI: CCI-000366

Discussion

IIS application pools can be periodically recycled to avoid unstable states possibly leading to application crashes, hangs, or memory leaks. By default, application pool recycling is overlapped, which means the worker process to be shut down is kept running until after a new worker process is started. After a new worker process starts, new requests are passed to it. The old worker process shuts down after it finishes processing its existing requests, or after a configured time-out, whichever comes first. This way of recycling ensures uninterrupted service to clients.

Checks

Note: Recycling Application Pools can create an unstable environment in a 64-bit SharePoint environment. If operational issues arise, with supporting documentation from the ISSO this check can be downgraded to a Cat III.

Note: If the IIS Application Pool is hosting Microsoft SharePoint, this is Not Applicable.

Open the IIS 8.5 Manager.

Perform for each Application Pool.

Click the “Application Pools”.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling" section and verify the value for "Private Memory Limit" is set to a value other than "0".

If the "Private Memory Limit" is set to a value of "0", this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling" section and set the value for "Private Memory Limit" to a value other than "0".
V-76873 No Change
Findings ID: IISW-SI-000255 Rule ID: SV-91569r1_rule Severity: medium CCI: CCI-000366

Discussion

Application pools can be periodically recycled to avoid unstable states possibly leading to application crashes, hangs, or memory leaks.

Checks

Note: Recycling Application Pools can create an unstable environment in a 64-bit SharePoint environment. If operational issues arise, with supporting documentation from the ISSO this check can be downgraded to a Cat III.

Open the IIS 8.5 Manager.

Perform for each Application Pool.

Click the “Application Pools”.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling" section and expand the "Generate Recycle Event Log Entry" section.

Verify both the "Regular time interval" and "Specific time" options are set to "True".

If both the "Regular time interval" and "Specific time" options are not set to "True", this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool and click "Advanced Settings" in the “Action” Pane.

Scroll down to the "Recycling" section and expand the "Generate Recycle Event Log Entry" section.

Set both the "Regular time interval" and "Specific time" options to "True".
V-76875 No Change
Findings ID: IISW-SI-000256 Rule ID: SV-91571r1_rule Severity: medium CCI: CCI-000366

Discussion

In order to determine the possible causes of client connection errors and to conserve system resources, it is important to both log errors and manage those settings controlling requests to the application pool.

Checks

Open the IIS 8.5 Manager.

Perform for each Application Pool.

Click the “Application Pools”.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "General" section and verify the value for "Queue Length" is set to 1000.

If the "Queue Length" is set to "1000" or less, this is not a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the “General” section and set the value for “Queue Length” to “1000” or less.

Click “OK”.
V-76877 No Change
Findings ID: IISW-SI-000257 Rule ID: SV-91573r1_rule Severity: medium CCI: CCI-000366

Discussion

Windows Process Activation Service (WAS) manages application pool configurations and may flag a worker process as unhealthy and shut it down. An application pool’s pinging monitor must be enabled to confirm worker processes are functional. A lack of response from the worker process might mean the worker process does not have a thread to respond to the ping request, or it is hanging for some other reason. The ping interval and ping response time may need adjustment to gain access to timely information about application pool health without triggering false, unhealthy conditions; for example, instability caused by an application.

Checks

Open the Internet Information Services (IIS) Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Process Model" section and verify the value for "Ping Enabled" is set to "True".

If the value for "Ping Enabled" is not set to "True", this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Process Model" section and set the value for "Ping Enabled" to "True".

Click “OK”.
V-76879 No Change
Findings ID: IISW-SI-000258 Rule ID: SV-91575r1_rule Severity: medium CCI: CCI-000366

Discussion

Rapid fail protection is a feature that interrogates the health of worker processes associated with websites and web applications. It can be configured to perform a number of actions such as shutting down and restarting worker processes that have reached failure thresholds. By not setting rapid fail protection the web server could become unstable in the event of a worker process crash potentially leaving the web server unusable.

Checks

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Rapid Fail Protection" section and verify the value for "Enabled" is set to "True".

If the "Rapid Fail Protection:Enabled" is not set to "True", this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Rapid Fail Protection" section and set the value for "Enabled" to "True".

Click “OK”.
V-76881 No Change
Findings ID: IISW-SI-000259 Rule ID: SV-91577r1_rule Severity: medium CCI: CCI-000366

Discussion

Windows Process Activation Service (WAS) manages application pool configuration and may flag a worker process as unhealthy and shut it down. The rapid fail protection must be set to a suitable value. A lack of response from the worker process might mean the worker process does not have a thread to respond to the ping request, or that it is hanging for some other reason. The ping interval and ping response time may need adjustment to gain access to timely information about application pool health without triggering false, unhealthy conditions.

Checks

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Rapid Fail Protection" section and verify the value for "Failure Interval" is set to "5".

If the "Failure Interval" is not set to "5" or less, this is a finding.

Fix

Open the IIS 8.5 Manager.

Click the “Application Pools”.

Perform for each Application Pool.

Highlight an Application Pool to review and click "Advanced Settings" in the "Actions" pane.

Scroll down to the "Rapid Fail Protection" section and set the value for "Failure Interval" to "5" or less.

Click “OK”.
V-76885 Updated
Findings ID: IISW-SI-000261 Rule ID: SV-91581r32_rule Severity: medium CCI: CCI-000381

Discussion

CGI and ASP scripts represent one of the most common and exploitable means of compromising a web server. All CGI and ASP program files must be segregated into their own unique folder to simplify the protection of these files. ASP scripts must be placed into a unique folder only containing other ASP scripts. JAVA and other technology-specific scripts must also be placed into their own unique folders. The placement of CGI, ASP, or equivalent scripts to special folders gives the Web Manager or the SA control over what goes into those folders and to facilitate access control at the folder level.

Checks

Determine whether scripts are used on the web server for the target website. Common file extensions include, but are not limited to: .cgi, .pl, .vb, .class, .c, .php, .asp, and .asp. x.

All interactive programs must be placed in unique designated folders based on CGI or ASP script type.

Open the IIS 8.5 Manager.

Right-click the IIS 8.5 web site name and select Explore.

Search for the listed script extensions. Each script type must be in its unique designated folder.

If scripts are not segregated from web content and in their own unique folders, then this is a finding.

Fix

All interactive programs must be placed in unique designated folders based on CGI or ASP script type.

Open the IIS 8.5 Manager.

Right-click the IIS 8.5 web server name and select Explore.

Search for the listed script extensions.

Move each script type to its unique designated folder.

Set the permissions to the scripts folders as follows:

Administrators: FULL
TrustedInstaller: FULL
SYSTEM: FULL
ApplicationPoolId:READ
Custom Service Account: READ
Users: READ
ALL APPLICATION PACKAGES: READ
V-76887 No Change
Findings ID: IISW-SI-000262 Rule ID: SV-91583r1_rule Severity: medium CCI: CCI-000381

Discussion

CGI is a programming standard for interfacing external applications with information servers, such as HTTP or web servers. CGI, represented by all upper case letters, should not be confused with the .cgi file extension. The .cgi file extension does represent a CGI script, but CGI scripts may be written in a number of programming languages (e.g., PERL, C, PHP, and JavaScript), each having their own unique file extension.

The use of CGI scripts represent one of the most common and exploitable means of compromising a web server. By definition, CGI scripts are executable by the operating system of the host server. While access control is provided via the web service, the execution of CGI programs is not limited unless the SA or the Web Manager takes specific measures. CGI programs can access and alter data files, launch other programs, and use the network.

Checks

Determine whether scripts are used on the web server for the subject website. Common file extensions include, but are not limited to: .cgi, .pl, .vb, .class, .c, .php, .asp, and .aspx.

If the website does not utilize CGI, this finding is Not Applicable.

All interactive programs must have restrictive permissions.

Open the IIS 8.5 Manager.

Right-click the IIS 8.5 web site name and select “Explore”.

Search for the listed script extensions.

Review the permissions to the CGI scripts and verify only the permissions listed, or more restrictive permissions are assigned.

Administrators: FULL
TrustedInstaller: FULL
ALL APPLICATION PACKAGES: Read
SYSTEM: FULL
ApplicationPoolId: READ
Custom Service Account: READ
Users: READ

If the permissions are less restrictive than listed above, this is a finding.

Fix

Determine whether scripts are used on the web server for the subject website. Common file extensions include, but are not limited to: .cgi, .pl, .vb, .class, .c, .php, .asp, and .aspx.

If the website does not utilize CGI, this finding is NA.

All interactive programs must have restrictive permissions.

Open the IIS 8.5 Manager.

Right-click the IIS 8.5 web server name and select “Explore”.

Search for the listed script extensions.

Set the permissions to the CGI scripts as follows:

Administrators: FULL
TrustedInstaller: FULL
ALL APPLICATION PACKAGES: Read
SYSTEM: FULL
ApplicationPoolId: READ
Custom Service Account: READ
Users: READ
V-76889 No Change
Findings ID: IISW-SI-000263 Rule ID: SV-91585r1_rule Severity: medium CCI: CCI-000381

Discussion

Copies of backup files will not execute on the server, but they can be read by the anonymous user if special precautions are not taken. Such backup copies contain the same sensitive information as the actual script being executed and, as such, are useful to malicious users. Techniques and systems exist today to search web servers for such files and are able to exploit the information contained in them.

Checks

Determine whether scripts are used on the web server for the subject website. Common file extensions include, but are not limited to: .cgi, .pl, .vb, .class, .c, .php, .asp, and .aspx.

If the website does not utilize CGI, this finding is Not Applicable.

Open the IIS 8.5 Manager.

Right-click the IIS 8.5 web site name and select “Explore”.

Search for the listed script extensions

Search for the following files: *.bak, *.old, *.temp, *.tmp, *.backup, or “copy of...”.

If files with these extensions are found, this is a finding.

Fix

Remove the backup files from the production web server.
V-76891 No Change
Findings ID: IISW-SI-000264 Rule ID: SV-91587r1_rule Severity: medium CCI: CCI-000366

Discussion

A consent banner will be in place to make prospective entrants aware that the website they are about to enter is a DoD web site and their activity is subject to monitoring. The document, DoDI 8500.01, establishes the policy on the use of DoD information systems. It requires the use of a standard Notice and Consent Banner and standard text to be included in user agreements. The requirement for the banner is for websites with security and access controls. These are restricted and not publicly accessible. If the website does not require authentication/authorization for use, then the banner does not need to be present. A manual check of the document root directory for a banner page file (such as banner.html) or navigation to the website via a browser can be used to confirm the information provided from interviewing the web staff.

Checks

Note: This requirement is only applicable for private DoD websites.

If a banner is required, the following banner page must be in place:

“You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.

By using this IS (which includes any device attached to this IS), you consent to the following conditions:

-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.

- At any time, the USG may inspect and seize data stored on this IS.

- Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.

- This IS includes security measures (e.g., authentication and access controls) to protect USG interests—not for your personal benefit or privacy.

- Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.”

OR

If your system cannot meet the character limits to store this amount of text in the banner, the following is another option for the warning banner:

"I've read & consent to terms in IS user agreem't."

NOTE: While DoDI 8500.01 does not contain a copy of the banner to be used, it does point to the RMF Knowledge Service for a copy of the required text. It is also noted that the banner is to be displayed only once when the individual enters the site and not for each page.

If the access-controlled website does not display this banner page before entry, this is a finding.

Fix

Configure a DoD private website to display the required DoD banner page when authentication is required for user access.