Microsoft Dot Net Framework 4.0 STIG

U_MS_DotNet_Framework4_V1R2_Manual-xccdf.xml

Version/Release Published Filters Downloads Update
V1R2 2014-01-08      
Update existing CKLs to this version of the STIG
Applicable to systems and applications utilizing the Microsoft .Net version 4.0 framework.
Vuln Rule Version CCI Severity Title Description
SV-7438r2_rule APPNET0031 MEDIUM Digital signatures assigned to strongly named assemblies must be verified. A strong name consists of the assembly's identity, simple text name, version number, and culture information (if provided)—plus a public key and a digital signature. Strong names serve to identify the author of the code. If digital signatures used to sign strong name assemblies are not verified, any self signed code can be impersonated. This can lead to a loss of system integrity. System AdministratorDCSL-1
SV-7444r2_rule APPNET0046 MEDIUM Windows systems must be configured to prevent application use of Test Root certificates. Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. A root certificate is a public key certificate or self signed certificate that identifies the Root Certificate Authority. Digital certificates are verified by using a chain of trust. The trust anchor for digital certificates is the Root Certificate Authority (CA). A CA may generate a Test Root Certificate that is used for testing purposes. Configuring production Windows systems to allow applications to use Test Root Certificates in order to ascertain trust can create an integrity risk.Systems that are compliant with this STIG requirement, may experience operational issues when attempting to run or install signed applications and device drivers that have been signed with a test root certificate. This is due to the production system being configured to require that certificates marked as being for test purposes only are not used. System AdministratorDCSL-1
SV-7445r2_rule APPNET0047 MEDIUM Windows must check for expired application certificates Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. If the system is not configured properly, Authenticode will not check for expired certificates creating an integrity risk which could result in malware running on the system. APPNET0047_MITSystems that are compliant with this STIG requirement and have restricted or no network access, may experience operational issues when attempting to run or install signed applications or drivers. This is due to the system being configured to require certificate validation prior to running the application, yet not having the means to communicate with the CA in order to validate the certificate. To address this issue, the DAA may accept the risk of reconfiguring the system back to factory default settings (23c00) for the time required to install the signed application. To mitigate the risk of not automatically validating the certificate when installing on an isolated network or system, the installer must manually validate the certificate of the signed application prior to installation. One way this can be accomplished is by using the Signtool.exe utility found in the Windows SDK. Signtool.exe provides the capability to manually validate the application signing certificate. See usage documentation for instructions on use. Another validation method is to install the application on a .NET STIG compliant system in a test environment that provides an available network path to the signing CA, then ensuring and documenting that no certificate notifications or issues were encountered. System AdministratorDCSL-1
SV-7446r2_rule APPNET0048 MEDIUM Developer certificates used with the .NET Publisher Membership Condition must be approved by the IAO. A .Net assembly will satisfy the Publisher Membership Condition if it is signed with a software publisher’s Authenticode X.509v3 digital certificate that can be verified by the Windows operating system as having a chain of trust that leads to a trusted root certificate stored in the user’s certificate store. The Publisher Membership Condition can be used to identify an organization, developer, vendor, or other entity as the ultimate source of the assembly, even if the code itself was obtained from a third party, such as a mirror site. Access to system resources, such as file systems or printers, may then be granted to the assembly based on the trust relationship with the identified entity. Certificates used to sign assemblies so the Publisher Member Condition may be applied must originate from a trusted source. Using a certificate that is not from a trusted source could potentially violate system integrity and confidentiality.System AdministratorDCSL-1
SV-41559r1_rule APPNET0049 MEDIUM Windows must be configured to check for revoked application certificates. Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. If the system is not configured properly, Authenticode will not check for revoked certificates creating an integrity risk that could result in malware being run on the system. APPNET0049_MITSystems that are compliant with this STIG requirement and have restricted or no network access, may experience operational issues when attempting to run or install signed applications. This is due to the system being configured to require certificate validation checks prior to running the application, yet not having the means to communicate with the CA in order to validate the certificate. To address this issue, the DAA may accept the risk of reconfiguring the system back to factory default settings (23c00) for the time required to install the signed application. To mitigate the risk of not automatically validating the certificate when installing on an isolated network or system, the installer must manually validate the certificate of the signed application prior to installation. One way this can be accomplished is by using the Signtool.exe utility found in the Windows SDK. Signtool.exe provides the capability to manually validate the application signing certificate. See usage documentation for instructions on use. Another validation method is to install the application on a .NET STIG compliant system in a test environment that provides an available network path to the signing CA, then ensuring and documenting that no certificate notifications or issues were encountered. System AdministratorDCSL-1
SV-7448r2_rule APPNET0050 MEDIUM Windows must be configured to block application execution if certificate server status is unavailable. Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. Certificate validation tests include certificate revocation checks to determine if the certificate has been revoked by the certificate authority. In order for Authenticode to test the certificate for revocation, the authoritative revocation server must be available. If the revocation server is not available, the certificate status is unknown and the software must be prevented from running until the certificate can be validated. By default, Windows will allow application software to run if the certificate revocation server is offline and not available. This creates an integrity risk of malware being introduced into the system. APPNET0050_MITSystems that are compliant with this STIG requirement and have restricted or no network access, may experience operational issues when attempting to run or install signed applications or drivers. This is due to the system being configured to require certificate server status validation prior to running the application, yet not having the means to communicate with the CA in order to validate the certificate. To address this issue, the DAA may accept the risk of reconfiguring the system back to factory default settings (23c00) for the time required to install the signed application. To mitigate the risk of not automatically validating the certificate server availability status when installing on an isolated network or system, the installer must manually validate certificate server availability prior to application installation. One way this can be accomplished is by using the Signtool.exe utility found in the Windows SDK. Signtool.exe provides the capability to manually validate the application signing certificate. See usage documentation for instructions on use. Another validation method is to install the application on a .NET STIG compliant system in a test environment that provides an available network path to the signing CA server, then ensuring and documenting that no certificate notifications or issues were encountered. System AdministratorDCSL-1
SV-7449r3_rule APPNET0051 MEDIUM Windows must be configured to check the time stamp servers certificate for revocation. Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. As part of the overall signing process, a trusted time stamp server also digitally signs the assembly. The time stamp server's signature confirms the developer's certificate was valid at the time the developer signed the assembly. If the system is not configured properly, Authenticode will not check for revocation of the time stamp server’s certificate. Not checking for certificate revocation creates a risk that could lead to a loss of system integrity. APPNET0051_MITSystems that are compliant with this STIG requirement and have restricted or no network access, may experience operational issues when attempting to run or install signed applications or drivers. This is due to the system being configured to require certificate validation prior to running the application, yet not having the means to communicate with the CA in order to validate the certificate. To address this issue, the DAA may accept the risk of reconfiguring the system back to factory default settings (23c00) for the time required to install the signed application. To mitigate the risk of not automatically validating the time stamp certificate when installing on an isolated network or system, the installer must manually validate the certificate of the signed application prior to installation. One way this can be accomplished is by using the Signtool.exe utility found in the Windows SDK. Signtool.exe provides the capability to manually validate the application signing certificate. See usage documentation for instructions on use. Another validation method is to install the application on a .NET STIG compliant system in a test environment that provides an available network path to the signing CA, then ensuring and documenting that no certificate notifications or issues were encountered.System AdministratorDCSL-1
SV-7450r2_rule APPNET0052 MEDIUM Encryption keys used for the .NET Strong Name Membership Condition must be protected. The Strong Name Membership condition requires that member assemblies be defined with Strong Names. A strong name consists of the assembly's identity, simple text name, version number, and culture information (if provided) — plus a public key and a digital signature. If assemblies do not have a strong name assigned, the assembly cannot be unique and the author of the code cannot be uniquely identified. In order to create the strong name, the developer must use a cryptographic key pair to sign the assembly. If the developer does not protect the key, the key can be stolen and used to sign any application, including malware applications. This could adversely affect application integrity and confidentiality.Systems ProgrammerDCSL-1
SV-7452r2_rule APPNET0055 MEDIUM CAS and policy configuration files must be backed up. A successful disaster recovery plan requires that CAS policy and CAS policy configuration files are identified and included in systems disaster backup and recovery events. Documentation regarding the location of system and application specific CAS policy configuration files and the frequency in which backups occur is required. If these files are not identified and the information is not documented, there is the potential that critical application configuration files may not be included in disaster recovery events which could lead to an availability risk.System AdministratorCODB-1, CODB-2
SV-7453r2_rule APPNET0060 MEDIUM Remoting Services HTTP channels must utilize authentication and encryption. .NET remoting provides the capability to build widely distributed applications. The application components may reside all on one computer or they may be spread out across the enclave. .NET client applications can make remoting calls to use objects in other processes on the same computer or on any other computer that is reachable over the network. .NET remoting can also be used to communicate with other application domains within the same process. Remoting is achieved via the exposure of endpoints that can be used to establish remote connectivity. Normally when application code attempts to access a protected resource, a stack walk is performed to ensure that all stack frames have permission to access the resource. However, with .Net 4.0, when a call is made on a remote object, this stack walk is not performed across the remoting boundary. The .Net remoting infrastructure requires FullTrust permission to execute on either the client or the server. Due to the fact that FullTrust permission is required, Remoting endpoints should be authenticated and encrypted in order to protect the system and the data. Microsoft provides 3 different "channels" that are used for remoting. They are HTTP, TCP and IPC. Any unauthorized use of a remoting application provides unauthorized access with FullTrust permissions to the system. This can potentially result in a loss of system integrity or confidentiality. System AdministratorDCSL-1
SV-55642r1_rule APPNET0061 MEDIUM .Net Framework versions installed on the system must be supported. Unsupported software introduces risks and violates DoD policy. Applications utilizing unsupported versions of .NET introduce substantial risk to the host, network, and the enclave by virtue of the fact they leverage an architecture that is no longer updated by the vendor. This introduces potential application integrity, availability, or confidentiality issues.COMS-1
SV-40966r1_rule APPNET0062 MEDIUM The .NET CLR must be configured to use FIPS approved encryption modules. FIPS encryption is configured via .NET configuration files. There are numerous configuration files that affect different aspects of .Net behavior. The .NET config files are described below. Machine Configuration Files: The machine configuration file, Machine.config, contains settings that apply to an entire computer. This file is located in the %SYSTEMROOT%\Microsoft.NET\Framework\v4.0.30319\Config directory for 32 bit .NET 4 installations and %SYSTEMROOT%\Microsoft.NET\Framework64\v4.0.30319\Config for 64 bit systems. Machine.config contains configuration settings for machine-wide assembly binding, built-in remoting channels, and ASP.NET. Application Configuration Files: Application configuration files contain settings specific to an application. If checking these files, a .NET review of a specific .NET application is most likely being conducted. These files contain configuration settings that the Common Language Runtime reads (such as assembly binding policy, remoting objects, and so on), and settings that the application can read. The name and location of the application configuration file depends on the application's host, which can be one of the following: Executable–hosted application configuration files. The configuration file for an application hosted by the executable host is in the same directory as the application. The name of the configuration file is the name of the application with a .config extension. For example, an application called myApp.exe can be associated with a configuration file called myApp.exe.config. Internet Explorer-hosted application configuration files. If an application hosted in Internet Explorer has a configuration file, the location of this file is specified in a tag with the following syntax. In this tag, "location" represents a URL that point to the configuration file. This sets the application base. The configuration file must be located on the same web site as the application. .NET 4.0 allows the CLR runtime to be configured to ignore FIPS encryption requirements. If the CLR is not configured to use FIPS encryption modules, insecure encryption modules might be employed which could introduce an application confidentiality or integrity issue. System AdministratorWeb AdministratorDCNR-1
SV-40977r1_rule APPNET0063 MEDIUM .NET must be configured to validate strong names on full-trust assemblies. The "bypassTrustedAppStrongNames" setting specifies whether the bypass feature that avoids validating strong names for full-trust assemblies is enabled. By default the bypass feature is enabled in .Net 4, therefore strong names are not validated for correctness when the assembly/program is loaded. Not validating strong names provides a faster application load time but at the expense of performing certificate validation. Full trust assemblies are .Net applications launched from the local host. Strong names are digital signatures tied to .Net applications/assemblies. .Net 4 considers applications installed locally to be fully trusted by default and grants these applications full permissions to access host resources. The bypass feature applies to any assembly signed with a strong name and having the following characteristics: Fully trusted without the StrongName evidence (for example, has MyComputer zone evidence). Loaded into a fully trusted AppDomain. Loaded from a location under the ApplicationBase property of that AppDomain. Not delay-signed. Not validating the certificates used to sign strong name assemblies will provide a faster application load time, but falsely assumes that signatures used to sign the application are to be implicitly trusted. Not validating strong name certificates introduces an integrity risk to the system.System AdministratorDCSL-1
SV-40979r1_rule APPNET0064 LOW .Net applications that invoke NetFx40_LegacySecurityPolicy must apply previous versions of .NET STIG guidance. CAS policy is .NET runtime version-specific. In .NET Framework version 4, CAS policy is disabled by default however; it can be re-enabled by using the NetFx40_LegacySecurityPolicy setting on a per application basis. When invoking the NetFx40_LegacySecurityPolicy setting in .NET 4, earlier versions of the .NET Framework CAS policy will become active therefore previous .NET STIG guidance that applies to the reactivated versions must also be applied. Failure to apply applicable versions of STIG guidance can result in the loss of system confidentiality, integrity or availability. System AdministratorDCSL-1
SV-41010r1_rule APPNET0065 MEDIUM Trust must be established prior to enabling the loading of remote code in .Net 4. In the .NET Framework version 3.5 and earlier versions, if an application assembly loaded code/objects from a remote location, that assembly would run partially trusted with a permissions grant set that depended on the zone in which it was loaded. For example, if an assembly was loaded from a web site, it was loaded into the Internet zone and granted the Internet permission set. In other words, it was executed in an Internet sandbox. If the same program is run in the .NET Framework version 4, an exception is thrown which effectively states; either explicitly create a sandbox for the assembly or run it in full trust. The element specifies the assemblies that run partially trusted in earlier versions of the .NET Framework will be run fully trusted in the .NET Framework 4. If loadFromRemoteSources is set to true, the remotely loaded application code is granted full trust. This could create an integrity vulnerability on the system. The required method to address this is to explicitly create a sandboxed environment for the remotely loaded code to run in rather than allowing remotely loaded code to run with full trust. The appropriate level of trust must be established prior to enabling the loading of remote code in .Net 4 applications and that code must be run in a controlled environment. The following is an example of the use of loadFromRemoteSources. Systems ProgrammerSystem AdministratorDCFA-1, DCSL-1
SV-41014r1_rule APPNET0066 LOW .NET default proxy settings must be reviewed and approved. The .Net framework can be configured to utilize a different proxy or altogether bypass the default proxy settings in the client's browser. This may lead to the framework using a proxy that is not approved for use. If the proxy is malicious, this could lead to a loss of application integrity and confidentiality.System AdministratorSystems ProgrammerDCFA-1, DCSL-1
SV-41030r1_rule APPNET0070 MEDIUM Software utilizing .Net 4.0 must be identified and relevant access controls configured. With the advent of .Net 4.0, the .Net framework no longer directly configures or enforces security policy for .Net applications. This task is now relegated to the operating system layer and the security protections built-in to .Net application "runtime hosts" that run on the O.S. Examples of these .Net "runtime hosts" include; Internet Explorer, Windows Shell, ASP.NET, Database Engines or any other "runtime hosts" that utilize .Net and load the .Net CLR. Security protections include utilizing runtime host security controls such as sandboxing to restrict or control application behavior as designed or required. To compensate for these design changes, Windows provides native solutions such as Software Security Policies (SSP) and Application Locker (AL) which are technologies that can be implemented via Group Policy (GPO). SSP, AL and similar third party solutions serve to restrict execution of applications, scripts and libraries based upon cryptographic hash, security zones, path and certificate values that are associated with the application files. Additionally, application developers will utilize "sandboxing" techniques within their code in order to isolate 3rd party code libraries from critical system resources. In order to assign protections to .Net 4.0 applications, the applications must first be identified and the appropriate hosting security mechanisms configured to accomplish that task. .Net STIG guidance cannot be applied if .Net applications are not identified and documented. The lack of an application inventory introduces confidentiality, availability and integrity vulnerabilities to the system.System AdministratorDCSL-1, DCSP-1
SV-41075r1_rule APPNET0067 MEDIUM Event tracing for Windows (ETW) for Common Language Runtime events must be enabled. Event tracing captures information about applications utilizing the .NET CLR and the .NET CLR itself. This includes security oriented information, such as Strong Name and Authenticode verification. Beginning with Windows Vista, ETW is enabled by default however, the .Net CLR and .Net applications can be configured to not utilize Event Tracing. If ETW event tracing is disabled, critical events that occurred within the runtime will not be captured in event logs.DCSL-1
SV-41412r1_rule APPNET0068 MEDIUM Windows must be configured to invalidate PKCS #7 version 1 signed objects Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. If the system is not configured properly, Authenticode will not invalidate older PKCS #7 version 1 signed objects creating a risk which could affect the integrity of the system. System AdministratorDCSL-1
SV-41581r1_rule APPNET0069 MEDIUM Software publishing state table must be configured to only trust items in the users trust database. Microsoft Windows operating systems provide a feature called Authenticode. Authenticode technology and its underlying code signing mechanisms serve to provide a mechanism to identify software publishers and ensure that software applications have not been tampered with. Authenticode technology relies on digital certificates and is based on Public Key Cryptography Standards (PKCS) #7 (encrypted key specification), PKCS #10 (certificate request formats), X.509 (certificate specification), and Secure Hash Algorithm (SHA) and MD5 hash algorithms. .Net application developers sign their application code with their public key and Authenticode technology performs certificate validation tasks prior to allowing the application to run. If the system is not configured properly, Authenticode will allow only downloads from publishers that are contained in users personal trust database creating an availability risk.System AdministratorDCSL-1
SV-42341r1_rule APPNET0071 MEDIUM Remoting Services TCP channels must utilize authentication and encryption. .NET remoting provides the capability to build widely distributed applications. The application components may reside all on one computer or they may be spread out across the enclave. .NET client applications can make remoting calls to use objects in other processes on the same computer or on any other computer that is reachable over the network. .NET remoting can also be used to communicate with other application domains within the same process. Remoting is achieved via the exposure of endpoints that can be used to establish remote connectivity. Normally when application code attempts to access a protected resource, a stack walk is performed to ensure that all stack frames have permission to access the resource. However, with .Net 4.0, when a call is made on a remote object, this stack walk is not performed across the remoting boundary. The .Net remoting infrastructure requires FullTrust permission to execute on either the client or the server. Due to the fact that FullTrust permission is required, Remoting endpoints should be authenticated and encrypted in order to protect the system and the data. Microsoft provides 3 different "channels" that are used for remoting. They are HTTP, TCP and IPC. Any unauthorized use of a remoting application provides unauthorized access with FullTrust permissions to the system. This can potentially result in a loss of system integrity or confidentiality.System Administrator