Apache Server 2.4 Windows Site Security Technical Implementation Guide

U_Apache_Server_2-4_Windows_Site_STIG_V1R0-1_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]
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Version / Release: V1R0

Published: 2018-11-26

Updated At: 2019-01-27 14:54:03

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Drop CKL or SCAP (XCCDF) results here.
    Vuln Rule Version CCI Severity Title Description Status Finding Details Comments
    AS24-W2-000010_rule AS24-W2-000010 CCI-000054 MEDIUM The Apache web server must limit the number of allowed simultaneous session requests. Web server management includes the ability to control the number of users and user sessions that utilize a web server. Limiting the number of allowed users and sessions per user is helpful in limiting risks related to several types of denial-of-service (DoS) attacks. Although there is some latitude concerning the settings, they should follow DoD-recommended values, but the settings should be configurable to allow for future DoD direction. While the DoD will specify recommended values, the values can be adjusted to accommodate the operational requirement of a given system.
    AS24-W2-000020_rule AS24-W2-000020 CCI-000054 MEDIUM The Apache web server must perform server-side session management. Session management is the practice of protecting the bulk of the user authorization and identity information. Storing of this data can occur on the client system or on the server. 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 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.
    AS24-W2-000030_rule AS24-W2-000030 CCI-000068 MEDIUM The Apache web server must use encryption strength in accordance with the categorization of data hosted by the Apache web server when remote connections are provided. The web server has several remote communications channels. Examples are user requests via http/https, communication to a backend database, and communication to authenticate users. The encryption used to communicate must match the data that is being retrieved or presented. Methods of communication are "http" for publicly displayed information, "https" to encrypt when user data is being transmitted, VPN tunneling, or other encryption methods to a database.
    AS24-W2-000040_rule AS24-W2-000040 CCI-001453 MEDIUM The Apache web server must use cryptography to protect the integrity of remote sessions. Data exchanged between the user and the web server can range from static display data to credentials used to log on to the hosted application. Even when data appears to be static, the non-displayed logic in a web page may expose business logic or trusted system relationships. The integrity of all the data being exchanged between the user and web server must always be trusted. To protect the integrity and trust, encryption methods should be used to protect the complete communication session.
    AS24-W2-000060_rule AS24-W2-000060 CCI-000213 MEDIUM The Apache web server must enforce approved authorizations for logical access to hosted applications and resources in accordance with applicable access control policies. To control access to sensitive information and hosted applications by entities that have been issued certificates by DoD-approved PKIs, the web server must be properly configured to incorporate a means of authorization that does not simply rely on the possession of a valid certificate for access. Access decisions must include a verification that the authenticated entity is permitted to access the information or application. Authorization decisions must leverage a variety of methods, such as mapping the validated PKI certificate to an account with an associated set of permissions on the system. If the web server relied only on the possession of the certificate and did not map to system roles and privileges, each user would have the same abilities and roles to make changes to the production system.
    AS24-W2-000090_rule AS24-W2-000090 CCI-000130 MEDIUM The Apache web server must produce log records containing sufficient information to establish what type of events occurred. 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 type of event that occurred is important during forensic analysis. The correct determination of the event and when it occurred is important in relation to other events that happened at that same time. Without sufficient information establishing what type of 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, and flow control rules invoked.
    AS24-W2-000130_rule AS24-W2-000130 CCI-000133 MEDIUM An Apache web server, behind a load balancer or proxy server, must produce log records containing the client IP information as the source and destination and not the load balancer or proxy IP information with each event. 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.
    AS24-W2-000140_rule AS24-W2-000140 CCI-000134 MEDIUM The Apache web server must produce log records that contain sufficient information to establish the outcome (success or failure) of events. 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, and flow control rules invoked.
    AS24-W2-000150_rule AS24-W2-000150 CCI-001487 MEDIUM The Apache web server must produce log records containing sufficient information to establish the identity of any user/subject or process associated with an event. 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.
    AS24-W2-000240_rule AS24-W2-000240 CCI-000381 MEDIUM The Apache web server must not perform user management for hosted applications. User management and authentication can be an essential part of any application hosted by the web server. Along with authenticating users, the user management function must perform several other tasks such as password complexity, locking users after a configurable number of failed logons, and management of temporary and emergency accounts. All of this must be done enterprise-wide. The web server contains a minimal user management function, but the web server user management function does not offer enterprise-wide user management, and user management is not the primary function of the web server. User management for the hosted applications should be done through a facility that is built for enterprise-wide user management, such as LDAP and Active Directory.
    AS24-W2-000300_rule AS24-W2-000300 CCI-000381 MEDIUM The Apache web server must have Multipurpose Internet Mail Extensions (MIME) that invoke OS shell programs disabled. 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.
    AS24-W2-000310_rule AS24-W2-000310 CCI-000381 MEDIUM The Apache web server must allow the mappings to unused and vulnerable scripts to be removed. Scripts allow server-side processing on behalf of the hosted application user or as processes needed in the implementation of hosted applications. Removing scripts not needed for application operation or deemed vulnerable helps to secure the web server. To ensure scripts are not added to the web server and run maliciously, script mappings that are not needed or used by the web server for hosted application operation must be removed.
    AS24-W2-000320_rule AS24-W2-000320 CCI-000381 MEDIUM The Apache web server must have resource mappings set to disable the serving of certain file types. 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 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.
    AS24-W2-000350_rule AS24-W2-000350 CCI-000381 MEDIUM Users and scripts running on behalf of users must be contained to the document root or home directory tree of the Apache web server. A web server is designed to deliver content and execute scripts or applications on the request of a client or user. Containing user requests to files in the directory tree of the hosted web application and limiting the execution of scripts and applications guarantees that the user is not accessing information protected outside the application's realm. The web server must also prohibit users from jumping outside the hosted application directory tree through access to the user's home directory, symbolic links or shortcuts, or through search paths for missing files.
    AS24-W2-000360_rule AS24-W2-000360 CCI-000382 MEDIUM The Apache web server must be configured to use a specified IP address and port. 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 use, 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.
    AS24-W2-000370_rule AS24-W2-000370 CCI-000197 MEDIUM The Apache web server must encrypt passwords during transmission. Data used to authenticate, especially passwords, needs to be protected at all times, and encryption is the standard method for protecting authentication data during transmission. Data used to authenticate can be passed to and from the web server for many reasons. Examples include data passed from a user to the web server through an HTTPS connection for authentication, the web server authenticating to a backend database for data retrieval and posting, and the web server authenticating to a clustered web server manager for an update.
    AS24-W2-000380_rule AS24-W2-000380 CCI-000185 MEDIUM The Apache web server must perform RFC 5280-compliant certification path validation. A certificate's certification path is the path from the end entity certificate to a trusted root certification authority (CA). Certification path validation is necessary for a relying party to make an informed decision regarding acceptance of an end entity certificate. Certification path validation includes checks such as certificate issuer trust, time validity, and revocation status for each certificate in the certification path. Revocation status information for CA and subject certificates in a certification path is commonly provided via certificate revocation lists (CRLs) or online certificate status protocol (OCSP) responses.
    AS24-W2-000390_rule AS24-W2-000390 CCI-000186 MEDIUM Only authenticated system administrators or the designated PKI Sponsor for the Apache web server must have access to the Apache web servers private key. The web server's private key is used to prove the identity of the server to clients and securely exchange the shared secret key used to encrypt communications between the web server and clients. By gaining access to the private key, an attacker can pretend to be an authorized server and decrypt the SSL traffic between a client and the web server.
    AS24-W2-000400_rule AS24-W2-000400 CCI-000803 MEDIUM The Apache web server must use cryptographic modules that meet the requirements of applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance when encrypting stored data. Encryption is only as good as the encryption modules used. Unapproved cryptographic module algorithms cannot be verified and cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised due to weak algorithms. FIPS 140-2 is the current standard for validating cryptographic modules, and NSA Type-X (where X=1, 2, 3, 4) products are NSA-certified, hardware-based encryption modules. The web server must provide FIPS-compliant encryption modules when storing encrypted data and configuration settings.
    AS24-W2-000410_rule AS24-W2-000410 CCI-000803 MEDIUM The Apache web server must use cryptographic modules that meet the requirements of applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance for such authentication. Encryption is only as good as the encryption modules used. Unapproved cryptographic module algorithms cannot be verified and cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised due to weak algorithms. FIPS 140-2 is the current standard for validating cryptographic modules, and NSA Type-X (where X=1, 2, 3, 4) products are NSA-certified, hardware-based encryption modules. The web server must provide FIPS-compliant encryption modules when authenticating users and processes.
    AS24-W2-000420_rule AS24-W2-000420 CCI-001166 MEDIUM An Apache web server using mobile code must meet DoD-defined mobile code requirements. Mobile code in hosted applications allows the developer to add functionality and displays to hosted applications that are fluid, as opposed to a static web page. The data presentation becomes more appealing to the user, is easier to analyze, and navigation through the hosted application and data is much less complicated. Some mobile code technologies in use in today's applications are Java, JavaScript, ActiveX, PDF, Postscript, Shockwave movies, Flash animations, and VBScript. The DoD has created policies that define the use of mobile code on DoD systems. The usage restrictions and implementation guidance apply to both the selection and use of mobile code installed on organizational servers and mobile code downloaded and executed on individual workstations. The web server may host applications that contain mobile code and therefore, must meet the DoD-defined requirements regarding the deployment and/or use of mobile code. This includes digitally signing applets to provide a means for the client to establish application authenticity.
    AS24-W2-000430_rule AS24-W2-000430 CCI-001082 MEDIUM Apache web server accounts accessing the directory tree, the shell, or other operating system functions and utilities must only be administrative accounts. As a rule, accounts on a web server are to be kept to a minimum. Only administrators, web managers, developers, auditors, and web authors require accounts on the machine hosting the web server. The resources to which these accounts have access must also be closely monitored and controlled. Only the system administrator needs access to all the system's capabilities, while the web administrator and associated staff require access and control of the web content and web server configuration files.
    AS24-W2-000440_rule AS24-W2-000440 CCI-001082 HIGH Anonymous user access to the Apache web server application directories must be prohibited. To properly monitor the changes to the web server and the hosted applications, logging must be enabled. Along with logging being enabled, each record must properly contain the changes made and the names of those who made the changes. Allowing anonymous users the capability to change the web server or the hosted application will not generate proper log information that can then be used for forensic reporting in the case of a security issue. Allowing anonymous users to make changes will also grant change capabilities to anybody without forcing a user to authenticate before the changes can be made.
    AS24-W2-000450_rule AS24-W2-000450 CCI-001082 MEDIUM The Apache web server must separate the hosted applications from hosted Apache web server management functionality. The separation of user functionality from web server management can be accomplished by moving management functions to a separate IP address or port. To further separate the management functions, separate authentication methods and certificates should be used. By moving the management functionality, the possibility of accidental discovery of the management functions by non-privileged users during hosted application use is minimized.
    AS24-W2-000460_rule AS24-W2-000460 CCI-001185 MEDIUM The Apache web server must invalidate session identifiers upon hosted application user logout or other session termination. Captured sessions can be reused in "replay" attacks. This requirement limits the ability of adversaries from capturing and continuing to employ previously valid session IDs. Session IDs are tokens generated by web applications to uniquely identify an application user's session. Unique session IDs help to reduce predictability of said identifiers. When a user logs out, or when any other session termination event occurs, the web server must terminate the user session to minimize the potential for an attacker to hijack that particular user session.
    AS24-W2-000470_rule AS24-W2-000470 CCI-001664 MEDIUM Cookies exchanged between the Apache web server and client, such as session cookies, must have security settings that disallow cookie access outside the originating Apache web server and hosted application. Cookies are used to exchange data between the web server and the client. Cookies, such as a session cookie, may contain session information and user credentials used to maintain a persistent connection between the user and the hosted application since HTTP/HTTPS is a stateless protocol. When the cookie parameters are not set properly (i.e., domain and path parameters), cookies can be shared within hosted applications residing on the same web server or to applications hosted on different web servers residing on the same domain.
    AS24-W2-000480_rule AS24-W2-000480 CCI-001664 MEDIUM The Apache web server must accept only system-generated session identifiers. Communication between a client and the web server is done using the HTTP protocol, but HTTP is a stateless protocol. 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 on to a hosted application. When a web server accepts session identifiers that are not generated by the web server, the web server creates an environment where session hijacking, such as session fixation, could be used to access hosted applications through session IDs that have already been authenticated. Forcing the web server to only accept web server-generated session IDs and to create new session IDs once a user is authenticated will limit session hijacking.
    AS24-W2-000500_rule AS24-W2-000500 CCI-001188 MEDIUM The Apache web server must generate unique session identifiers that cannot be reliably reproduced. Communication between a client and the web server is done using the HTTP protocol, but HTTP is a stateless protocol. 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 on to 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.
    AS24-W2-000510_rule AS24-W2-000510 CCI-001188 MEDIUM The Apache web server must generate a session ID long enough that it cannot be guessed through brute force. Generating a session identifier (ID) that is not easily guessed through brute force is essential to deter several types of session attacks. By knowing the session ID, an attacker can hijack a user session that has already been user authenticated by the hosted application. The attacker does not need to guess user identifiers and passwords or have a secure token since the user session has already been authenticated. Generating session IDs that are at least 128 bits (16 bytes) in length will cause an attacker to take a large amount of time and resources to guess, reducing the likelihood of an attacker guessing a session ID.
    AS24-W2-000520_rule AS24-W2-000520 CCI-001188 MEDIUM The Apache web server must generate a session ID using as much of the character set as possible to reduce the risk of brute force. Generating a session identifier (ID) that is not easily guessed through brute force is essential to deter several types of session attacks. By knowing the session ID, an attacker can hijack a user session that has already been user authenticated by the hosted application. The attacker does not need to guess user identifiers and passwords or have a secure token since the user session has already been authenticated. By generating session IDs that contain as much of the character set as possible, i.e., A-Z, a-z, and 0-9, the session ID becomes exponentially harder to guess.
    AS24-W2-000540_rule AS24-W2-000540 CCI-001190 MEDIUM The Apache web server must augment re-creation to a stable and known baseline. Making certain that the web server has not been updated by an unauthorized user is always a concern. Adding patches, functions, and modules that are untested and not part of the baseline opens the possibility for security risks. The web server must offer, and not hinder, a method that allows for the quick and easy reinstallation of a verified and patched baseline to guarantee the production web server is up-to-date and has not been modified to add functionality or expose security risks. When the web server does not offer a method to roll back to a clean baseline, external methods, such as a baseline snapshot or virtualizing the web server, can be used.
    AS24-W2-000560_rule AS24-W2-000560 CCI-001190 MEDIUM The Apache web server must be configured to provide clustering. The web server may host applications that display information that cannot be disrupted, such as information that is time critical or life threatening. In these cases, a web server that shuts down or ceases to be accessible when there is a failure is not acceptable. In these types of cases, clustering of web servers is used. Clustering of multiple web servers is a common approach to providing fail-safe application availability. To ensure application availability, the web server must provide clustering or some form of failover functionality.
    AS24-W2-000580_rule AS24-W2-000580 CCI-001084 MEDIUM The Apache web server document directory must be in a separate partition from the Apache web servers system files. A web server is used to deliver content on the request of a client. The content delivered to a client must be controlled, allowing only hosted application files to be accessed and delivered. To allow a client access to system files of any type is a major security risk that is entirely avoidable. Obtaining such access is the goal of directory traversal and URL manipulation vulnerabilities. To facilitate such access by misconfiguring the web document (home) directory is a serious error. In addition, having the path on the same drive as the system folder compounds potential attacks, such as drive space exhaustion.
    AS24-W2-000590_rule AS24-W2-000590 CCI-001094 MEDIUM The Apache web server must restrict the ability of users to launch denial-of-service (DoS) attacks against other information systems or networks. A web server can limit the ability of the web server being used in a DoS attack through several methods. The methods employed will depend upon the hosted applications and their resource needs for proper operation. An example setting that could be used to limit the ability of the web server being used in a DoS attack is bandwidth throttling.
    AS24-W2-000610_rule AS24-W2-000610 CCI-001312 MEDIUM The Apache web server must display a default hosted application web page, not a directory listing, when a requested web page cannot be found. The goal is to completely control the web user's 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. Enumeration techniques, such as URL parameter manipulation, rely upon being able to obtain information about the web server's directory structure by locating directories without default pages. In the scenario, the web server will display to the user a listing of the files in the directory being accessed. By having a default hosted application web page, the anonymous web user will not obtain directory browsing information or an error message that reveals the server type and version.
    AS24-W2-000620_rule AS24-W2-000620 CCI-001312 MEDIUM Warning and error messages displayed to clients must be modified to minimize the identity of the Apache web server, patches, loaded modules, and directory paths. Information needed by an attacker to begin looking for possible vulnerabilities in a web server includes any information about the web server, backend systems being accessed, and plug-ins or modules being used. Web servers will often display error messages to client users displaying enough information to aid in the debugging of the error. The information given back in error messages may display the web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage. This information could be used by an attacker to blueprint what type of attacks might be successful. The information given to users must be minimized to not aid in the blueprinting of the web server.
    AS24-W2-000630_rule AS24-W2-000630 CCI-001312 MEDIUM Debugging and trace information used to diagnose the Apache web server must be disabled. Information needed by an attacker to begin looking for possible vulnerabilities in a web server includes any information about the web server and plug-ins or modules being used. When debugging or trace information is enabled in a production web server, information about the web server, such as web server type, version, patches installed, plug-ins and modules installed, type of code being used by the hosted application, and any backends being used for data storage may be displayed. Since this information may be placed in logs and general messages during normal operation of the Apache web server, an attacker does not need to cause an error condition to gain this information.
    AS24-W2-000640_rule AS24-W2-000640 CCI-002361 MEDIUM The Apache web server must set an absolute timeout for sessions. 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 an absolute period of time, the user is forced to reauthenticate, guaranteeing the session is still in use. Enabling an absolute timeout for sessions closes sessions that are still active. Examples would be a runaway process accessing the web server or an attacker using a hijacked session to slowly probe the web server.
    AS24-W2-000650_rule AS24-W2-000650 CCI-002361 MEDIUM The Apache web server must set an inactive timeout for sessions. 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 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.
    AS24-W2-000660_rule AS24-W2-000660 CCI-002314 HIGH Remote access to the Apache web server must follow access policy or work in conjunction with enterprise tools designed to enforce policy requirements. Remote access to the web server is any access that communicates through an external, non-organization-controlled network. Remote access can be used to access hosted applications or to perform management functions. A web server can be accessed remotely and must be able to enforce remote access policy requirements or work in conjunction with enterprise tools designed to enforce policy requirements. Examples of the web server enforcing a remote access policy are implementing IP filtering rules, using "https" instead of "http" for communication, implementing secure tokens, and validating users.
    AS24-W2-000670_rule AS24-W2-000670 CCI-002314 MEDIUM The Apache web server must restrict inbound connections from nonsecure zones. Remote access to the web server is any access that communicates through an external, non-organization-controlled network. Remote access can be used to access hosted applications or to perform management functions. A web server can be accessed remotely and must be capable of restricting access from what the DoD defines as nonsecure zones. Nonsecure zones are defined as any IP, subnet, or region that is defined as a threat to the organization. The nonsecure zones must be defined for public web servers logically located in a DMZ, as well as private web servers with perimeter protection devices. By restricting access from nonsecure zones, through the internal web server access list, the web server can stop or slow denial-of-service (DoS) attacks on the web server.
    AS24-W2-000690_rule AS24-W2-000690 CCI-002235 MEDIUM Non-privileged accounts on the hosting system must only access Apache web server security-relevant information and functions through a distinct administrative account. By separating web server security functions from non-privileged users, roles can be developed that can then be used to administer the web server. Forcing users to change from a non-privileged account to a privileged account when operating on the web server or on security-relevant information forces users to only operate as a web server administrator when necessary. Operating in this manner allows for better logging of changes and better forensic information and limits accidental changes to the web server.
    AS24-W2-000700_rule AS24-W2-000700 CCI-001844 MEDIUM An Apache web server that is part of an Apache web server cluster must route all remote management through a centrally managed access control point. A web server cluster is a group of independent web servers that are managed as a single system for higher availability, easier manageability, and greater scalability. Without having centralized control of the web server cluster, management of the cluster becomes difficult. It is critical that remote management of the cluster be done through a designated management system acting as a single access point.
    AS24-W2-000770_rule AS24-W2-000770 CCI-001813 MEDIUM The Apache web server application, libraries, and configuration files must only be accessible to privileged users. A web server can be modified through parameter modification, patch installation, upgrades to the web server or modules, and security parameter changes. With each of these changes, there is the potential for an adverse effect such as a denial of service (DoS), web server instability, or hosted application instability. To limit changes to the web server and limit exposure to any adverse effects from the changes, files such as the web server application files, libraries, and configuration files must have permissions and ownership set properly to only allow privileged users access.
    AS24-W2-000780_rule AS24-W2-000780 CCI-001762 MEDIUM The Apache web server must prohibit or restrict the use of nonsecure or unnecessary ports, protocols, modules, and/or services. Web servers provide numerous processes, features, and functionalities that use 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 Ports, Protocols, and Services Management (PPSM) Category Assurance List (CAL) and vulnerability assessments.
    AS24-W2-000800_rule AS24-W2-000800 CCI-002470 MEDIUM The Apache web server must only accept client certificates issued by DoD PKI or DoD-approved PKI Certification Authorities (CAs). Non-DoD-approved PKIs have not been evaluated to ensure that they have security controls and identity vetting procedures in place that are sufficient for DoD systems to rely on the identity asserted in the certificate. PKIs lacking sufficient security controls and identity vetting procedures risk being compromised and issuing certificates that enable adversaries to impersonate legitimate users.
    AS24-W2-000810_rule AS24-W2-000810 CCI-002476 MEDIUM The Apache web server private website must employ cryptographic mechanisms (TLS) and require client certificates. 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.
    AS24-W2-000830_rule AS24-W2-000830 CCI-002385 MEDIUM The Apache web server must be tuned to handle the operational requirements of the hosted application. A denial of service (DoS) can occur when the web server is so overwhelmed that it can no longer respond to additional requests. A web server not properly tuned may become overwhelmed and cause a DoS condition even with expected traffic from users. To avoid a DoS, the web server must be tuned to handle the expected traffic for the hosted applications.
    AS24-W2-000840_rule AS24-W2-000840 CCI-002418 MEDIUM The Apache web server must employ cryptographic mechanisms (TLS/DTLS/SSL) preventing the unauthorized disclosure of information during transmission. Preventing the disclosure of transmitted information requires that the web server take measures to employ some form of cryptographic mechanism 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.
    AS24-W2-000850_rule AS24-W2-000850 CCI-002418 MEDIUM The Apache web server session IDs must be sent to the client using SSL/TLS. 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.
    AS24-W2-000860_rule AS24-W2-000860 CCI-002418 MEDIUM The Apache web server cookies, such as session cookies, sent to the client using SSL/TLS must not be compressed. 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 can 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.
    AS24-W2-000870_rule AS24-W2-000870 CCI-002418 MEDIUM Cookies exchanged between the Apache web server and the client, such as session cookies, must have cookie properties set to prohibit client-side scripts from reading the cookie data. 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.
    AS24-W2-000880_rule AS24-W2-000880 CCI-002418 MEDIUM Cookies exchanged between the Apache web server and the client, such as session cookies, must have cookie properties set to force the encryption of cookies. Cookies can be sent to a client using TLS/SSL to encrypt the cookies, but TLS/SSL is not used by every hosted application since the data being displayed does not require the encryption of the transmission. To safeguard against cookies, especially session cookies, being sent in plaintext, a cookie can be encrypted before transmission. To force a cookie to be encrypted before transmission, the cookie "Secure" property can be set.
    AS24-W2-000890_rule AS24-W2-000890 CCI-002418 HIGH An Apache web server must maintain the confidentiality of controlled information during transmission through the use of an approved TLS version. Transport Layer Security (TLS) is a required transmission protocol for a web server hosting controlled information. The use of TLS provides confidentiality of data in transit between the web server and client. FIPS 140-2 approved TLS versions must be enabled and non-FIPS-approved SSL versions must be disabled. NIST SP 800-52 defines the approved TLS versions for government applications.
    AS24-W2-000910_rule AS24-W2-000910 CCI-002420 MEDIUM The Apache web server must maintain the confidentiality and integrity of information during preparation for transmission. 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.
    AS24-W2-000920_rule AS24-W2-000920 CCI-002422 MEDIUM The Apache web server must maintain the confidentiality and integrity of information during reception. 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 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 use approved encryption when receiving transmitted data.
    AS24-W2-000950_rule AS24-W2-000950 CCI-000366 LOW The Apache web server must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. Configuring the web server to implement organization-wide security implementation guides and security checklists guarantees compliance with federal standards and establishes a common security baseline across the DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed that affect the security posture and/or functionality of the system. Security-related parameters are parameters impacting the security state of the web server, including the parameters required to satisfy other security control requirements.