Microsoft Windows Server 2025 Security Technical Implementation Guide

Security flaws with operating systems are discovered daily. Vendors are constantly updating and patching their products to address newly discovered security vulnerabilities. Organizations (including any contractor to the organization) are required to promptly install security-relevant software updates (e.g., patches, service packs, and hot fixes). Flaws discovered during security assessments, continuous monitoring, incident response activities, or information system error handling must also be addressed expeditiously.

Using a privileged account to perform routine functions makes the computer vulnerable to malicious software inadvertently introduced during a session that has been granted full privileges.

Using applications that access the internet or have potential internet sources using administrative privileges exposes a system to compromise. If a flaw in an application is exploited while running as a privileged user, the entire system could be compromised. Web browsers and email are common attack vectors for introducing malicious code and must not be run with an administrative account.

Since administrative accounts may generally change or work around technical restrictions for running a web browser or other applications, it is essential that policy require administrative accounts to not access the internet or use applications such as email.

The policy must define specific exceptions for local service administration. These exceptions may include HTTP(S)-based tools that are used for the administration of the local system, services, or attached devices.

Allow listing can be used to enforce the policy to ensure compliance.

Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000205-GPOS-00083

Application/service account passwords must be of sufficient length to prevent being easily cracked. Application/service accounts that are manually managed must have passwords at least 15 characters in length.

Shared accounts (accounts where two or more people log on with the same user identification) do not provide adequate identification and authentication. There is no way to provide for nonrepudiation or individual accountability for system access and resource usage.

Credential Guard uses virtualization-based security to protect data that could be used in credential theft attacks if compromised. A number of system requirements must be met for Credential Guard to be configured and enabled properly. Without a TPM enabled and ready for use, Credential Guard keys are stored in a less secure method using software.

A properly configured host-based intrusion detection system (HIDS) or host-based intrusion prevention system (HIPS) provides another level of defense against unauthorized access to critical servers. With proper configuration and logging enabled, such a system can stop and/or alert for many attempts to gain unauthorized access to resources.

Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications.

The default permissions are adequate when the Security Option "Network access: Let Everyone permissions apply to anonymous users" is set to "Disabled" (WN25-SO-000240).

Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124

Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications.

The default permissions are adequate when the Security Option "Network access: Let Everyone permissions apply to anonymous users" is set to "Disabled" (WN25-SO-000240).

Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124

Windows shares are a means by which files, folders, printers, and other resources can be published for network users to access. Improper configuration can permit access to devices and data beyond a user's need.

The lack of password protection enables anyone to gain access to the information system, which opens a backdoor opportunity for intruders to compromise the system as well as other resources. Accounts on a system must require passwords.

Monitoring system files for changes against a baseline on a regular basis may help detect the possible introduction of malicious code on a system.

Use of software certificates and their accompanying installation files for end users to access resources is less secure than the use of hardware-based certificates.

Information can be either unintentionally or maliciously disclosed or modified during preparation for transmission, 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.

Ensuring the confidentiality of transmitted information requires the operating system to take measures in preparing information for transmission. This can be accomplished via access control and encryption.

Use of this requirement will be limited to situations where the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process. When transmitting data, operating systems need to support transmission protection mechanisms such as TLS, encrypted VPNs, or IPsec.

Satisfies: SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190

A firewall provides a line of defense against attack, allowing or blocking inbound and outbound connections based on a set of rules.

Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232

Emergency administrator accounts are privileged accounts established in response to crisis situations where the need for rapid account activation is required. Therefore, emergency account activation may bypass normal account authorization processes. If these accounts are automatically disabled, system maintenance during emergencies may not be possible, thus adversely affecting system availability.

Emergency administrator accounts are different from infrequently used accounts (i.e., local logon accounts used by system administrators when network or normal logon/access is not available). Infrequently used accounts are not subject to automatic termination dates. Emergency accounts are accounts created in response to crisis situations, usually for use by maintenance personnel. The automatic expiration or disabling time period may be extended as needed until the crisis is resolved; however, it must not be extended indefinitely. A permanent account must be established for privileged users who need long-term maintenance accounts.

To address access requirements, many operating systems can be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements.

Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption.

Unnecessary applications and/or services such as Bluetooth could allow an attacker to connect with intentions to take over or disrupt the system.

Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.

Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.

SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks, as well as not being FIPS compliant.

Windows PowerShell 5.x added advanced logging features that can provide additional detail when malware has been run on a system. Disabling the Windows PowerShell 2.0 mitigates against a downgrade attack that evades the Windows PowerShell 5.x script block logging feature.

The FTP service allows remote users to access shared files and directories that could provide access to system resources and compromise the system, especially if the user can gain access to the root directory of the boot drive.

Accounts or groups given rights on a system may show up as unresolved SIDs for various reasons including deletion of the accounts or groups. If the account or group objects are reanimated, there is a potential they may still have rights no longer intended. Valid domain accounts or groups may also show up as unresolved SIDs if a connection to the domain cannot be established.

Secure Boot is a standard that ensures systems boot only to a trusted operating system. Secure Boot is required to support additional security features in Windows, including Virtualization Based Security and Credential Guard. If Secure Boot is turned off, these security features will not function.

The account lockout feature, when enabled, prevents brute-force password attacks on the system. The higher this value is, the less effective the account lockout feature will be in protecting the local system. The number of bad logon attempts must be reasonably small to minimize the possibility of a successful password attack while allowing for honest errors made during normal user logon.

A system is more vulnerable to unauthorized access when system users recycle the same password several times without being required to change to a unique password on a regularly scheduled basis. This enables users to effectively negate the purpose of mandating periodic password changes. The default value is "24" for Windows domain systems. DOD has decided this is the appropriate value for all Windows systems.

Permitting passwords to be changed in immediate succession within the same day allows users to cycle passwords through their history database. This enables users to effectively negate the purpose of mandating periodic password changes.

Storing passwords using reversible encryption is essentially the same as storing clear-text versions of the passwords, which are easily compromised. For this reason, this policy must never be enabled.

Protection of log data includes ensuring the log data is not accidentally lost or deleted. Audit information stored in one location is vulnerable to accidental or incidental deletion or alteration.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. The Security event log may disclose sensitive information or be susceptible to tampering if proper permissions are not applied.

Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029

Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information.

Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the modification or deletion of audit tools.

Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Credential Validation records events related to validation tests on credentials for a user account logon.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Security Group Management records events such as creating, deleting, or changing security groups, including changes in group members.

Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

User Account Management records events such as creating, changing, deleting, renaming, disabling, or enabling user accounts.

Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Process Creation records events related to the creation of a process and the source.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Account Lockout events can be used to identify potentially malicious logon attempts.

Satisfies: SRG-OS-000240-GPOS-00090, SRG-OS-000470-GPOS-00214

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Logoff records user logoffs. If this is an interactive logoff, it is recorded on the local system. If it is to a network share, it is recorded on the system accessed.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Logon records user logons. If this is an interactive logon, it is recorded on the local system. If it is to a network share, it is recorded on the system accessed.

Satisfies: SRG-OS-000032-GPOS-00013, SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Auditing for other object access records events related to the management of task scheduler jobs and COM+ objects.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Removable Storage auditing under Object Access records events related to access attempts on file system objects on removable storage devices.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Audit Policy Change records events related to changes in audit policy.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Authentication Policy Change records events related to changes in authentication policy, including Kerberos policy and Trust changes.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Sensitive Privilege Use records events related to use of sensitive privileges, such as "Act as part of the operating system" or "Debug programs".

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000755-GPOS-00220

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

IPsec Driver records events related to the IPsec Driver, such as dropped packets.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Audit Other System Events records information related to cryptographic key operations and the Windows Firewall service.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Security State Change records events related to changes in the security state, such as startup and shutdown of the system.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

System Integrity records events related to violations of integrity to the security subsystem.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222

Slide shows displayed on the lock screen could display sensitive information to unauthorized personnel. Turning off this feature will limit access to the information to a logged-on user.

Configuring the system to disable IP source routing protects against spoofing.

Configuring the system to ignore name release requests, except from WINS servers, prevents a denial-of-service (DoS) attack. The DoS consists of sending a NetBIOS name release request to the server for each entry in the server's cache, causing a response delay in the normal operation of the server's WINS resolution capability.

Additional security requirements are applied to UNC paths specified in hardened UNC paths before allowing access to them. This aids in preventing tampering with or spoofing of connections to these paths.

An exportable version of credentials is provided to remote hosts when using credential delegation, which exposes them to theft on the remote host. Restricted Admin mode or Remote Credential Guard allow delegation of nonexportable credentials providing additional protection of the credentials. Enabling this configures the host to support Restricted Admin mode or Remote Credential Guard.

Compromised boot drivers can introduce malware prior to protection mechanisms that load after initialization. The Early Launch Antimalware driver can limit allowed drivers based on classifications determined by the malware protection application. At a minimum, drivers determined to be bad must not be allowed.

Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Turning off this capability will prevent potentially sensitive information from being sent outside the enterprise and will prevent uncontrolled updates to the system.

This setting prevents the computer from downloading print driver packages over HTTP.

Enabling interaction with the network selection UI allows users to change connections to available networks without signing in to Windows.

A system that does not require authentication when resuming from sleep may provide access to unauthorized users. Authentication must always be required when accessing a system. This setting ensures users are prompted for a password when the system wakes from sleep (plugged in).

Allowing AutoPlay to execute may introduce malicious code to a system. AutoPlay begins reading from a drive as soon as media is inserted into the drive. As a result, the setup file of programs or music on audio media may start. This setting will disable AutoPlay for nonvolume devices, such as Media Transfer Protocol (MTP) devices.

Allowing AutoPlay to execute may introduce malicious code to a system. AutoPlay begins reading from a drive as soon media is inserted into the drive. As a result, the setup file of programs or music on audio media may start. By default, AutoPlay is disabled on removable drives, such as the floppy disk drive (but not the CD-ROM drive) and on network drives. Enabling this policy disables AutoPlay on all drives.

Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Limiting this capability will prevent potentially sensitive information from being sent outside the enterprise. The "send required diagnostic data" option for Allow Diagnostic Data configures the lowest amount of data, effectively none outside of the Malicious Software Removal Tool (MSRT), Defender, and Diagnostic Data client settings. "Optional Diagnostic Data" sends basic diagnostic and usage data and may be required to support some Microsoft services.

Inadequate log size will cause the log to fill up quickly. This may prevent audit events from being recorded properly and require frequent attention by administrative personnel.

Inadequate log size will cause the log to fill up quickly. This may prevent audit events from being recorded properly and require frequent attention by administrative personnel.

Data Execution Prevention provides additional protection by performing checks on memory to help prevent malicious code from running. This setting will prevent Data Execution Prevention from being turned off for File Explorer.

The shell protocol will limit the set of folders that applications can open when run in protected mode. Restricting files an application can open to a limited set of folders increases the security of Windows.

Preventing users from sharing the local drives on their client computers with Remote Session Hosts that they access helps reduce possible exposure of sensitive data.

Allowing unsecure RPC communication exposes the system to man-in-the-middle attacks and data disclosure attacks. A man-in-the-middle attack occurs when an intruder captures packets between a client and server and modifies them before allowing the packets to be exchanged. Usually, the attacker will modify the information in the packets in an attempt to cause either the client or server to reveal sensitive information.

Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000250-GPOS-00093

Attachments from RSS feeds may not be secure. This setting will prevent attachments from being downloaded from RSS feeds.

Indexing of encrypted files may expose sensitive data. This setting prevents encrypted files from being indexed.

Standard user accounts must not be granted elevated privileges. Enabling Windows Installer to elevate privileges when installing applications can allow malicious persons and applications to gain full control of a system.

Windows can be configured to automatically sign the user back in after a Windows Update restart. Some protections are in place to help ensure this is done in a secure fashion; however, disabling this will prevent the caching of credentials for this purpose and also ensure the user is aware of the restart.

Basic authentication uses plain-text passwords that could be used to compromise a system. Disabling Basic authentication will reduce this potential.

Digest authentication is not as strong as other options and may be subject to man-in-the-middle attacks. Disallowing Digest authentication will reduce this potential.

Unencrypted remote access to a system can allow sensitive information to be compromised. Windows remote management connections must be encrypted to prevent this.

Satisfies: SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Enabling PowerShell Transcription will record detailed information from the processing of PowerShell commands and scripts. This can provide additional detail when malware has run on a system.

This policy setting determines whether the Kerberos Key Distribution Center (KDC) validates every request for a session ticket against the user rights policy of the target computer. The policy is enabled by default, which is the most secure setting for validating that access to target resources is not circumvented.

Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058

In Kerberos, there are two types of tickets: Ticket Granting Tickets (TGTs) and Service Tickets. Kerberos tickets have a limited lifetime so the time an attacker has to implement an attack is limited. This policy controls how long TGTs can be renewed. With Kerberos, the user's initial authentication to the domain controller results in a TGT, which is then used to request Service Tickets to resources. Upon startup, each computer gets a TGT before requesting a service ticket to the domain controller and any other computers it needs to access. For services that start up under a specified user account, users must always get a TGT first and then get Service Tickets to all computers and services accessed.

Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058

This setting determines the maximum time difference (in minutes) that Kerberos will tolerate between the time on a client's clock and the time on a server's clock while still considering the two clocks synchronous. To prevent replay attacks, Kerberos uses timestamps as part of its protocol definition. For timestamps to work properly, the clocks of the client and the server must be in sync as much as possible.

Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058

Improper access permissions for directory data files could allow unauthorized users to read, modify, or delete directory data.

The SYSVOL directory contains public files (to the domain) such as policies and logon scripts. Data in shared subdirectories are replicated to all domain controllers in a domain.

When Active Directory objects do not have appropriate access control permissions, it may be possible for malicious users to create, read, update, or delete the objects and degrade or destroy the integrity of the data. When the directory service is used for identification, authentication, or authorization functions, a compromise of the database objects could lead to a compromise of all systems that rely on the directory service.

The Domain Controllers OU object requires special attention as the Domain Controllers are central to the configuration and management of the domain. Inappropriate access permissions defined for the Domain Controllers OU could allow an intruder or unauthorized personnel to make changes that could lead to the compromise of the domain.

When directory service data files, especially for directories used for identification, authentication, or authorization, reside on the same logical partition as user-owned files, the directory service data may be more vulnerable to unauthorized access or other availability compromises. Directory service and user-owned data files sharing a partition may be configured with less restrictive permissions to allow access to the user data.

The directory service may be vulnerable to a denial-of-service (DoS) attack when user-owned files on a common partition are expanded to an extent preventing the directory service from acquiring more space for directory or audit data.

Directory data that is not appropriately encrypted is subject to compromise. Commercial-grade encryption does not provide adequate protection when the classification level of directory data in transit is higher than the level of the network.

The failure to terminate inactive network connections increases the risk of a successful attack on the directory server. The longer an established session is in progress, the more time an attacker has to hijack the session, implement a means to passively intercept data, or compromise any protections on client access. For example, if an attacker gains control of a client computer, an existing (already authenticated) session with the directory server could allow access to the directory. The lack of confidentiality protection in LDAP-based sessions increases exposure to this vulnerability.

Satisfies: SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109

When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data.

For AD, there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the Domain object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data.

For AD, there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the Domain Controller OU object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data.

For AD, there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the RID Manager$ object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Audit Directory Service Access records events related to users accessing an Active Directory object.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior.

Audit Directory Service Changes records events related to changes made to objects in Active Directory Domain Services.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212

Domain controllers are part of the chain of trust for PKI authentications. Without the appropriate certificate, the authenticity of the domain controller cannot be verified. Domain controllers must have a server certificate to establish authenticity as part of PKI authentications in the domain.

A PKI implementation depends on the practices established by the Certificate Authority (CA) to ensure the implementation is secure. Without proper practices, the certificates issued by a CA have limited value in authentication functions.

Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182

Unsigned network traffic is susceptible to man-in-the-middle attacks, where an intruder captures packets between the server and the client and modifies them before forwarding them to the client. In the case of an LDAP server, this means that an attacker could cause a client to make decisions based on false records from the LDAP directory. The risk of an attacker pulling this off can be decreased by implementing strong physical security measures to protect the network infrastructure. Furthermore, implementing Internet Protocol security (IPsec) authentication header (AH) mode, which performs mutual authentication and packet integrity for IP traffic, can make all types of man-in-the-middle attacks extremely difficult.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Access this computer from the network" right may access resources on the system, and this right must be limited to those requiring it.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Allow log on through Remote Desktop Services" user right can access a system through Remote Desktop.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Deny log on as a batch job" user right defines accounts that are prevented from logging on to the system as a batch job, such as Task Scheduler.

The Guests group must be assigned to prevent unauthenticated access.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Deny log on locally" user right defines accounts that are prevented from logging on interactively.

The Guests group must be assigned this right to prevent unauthenticated access.

Weak mappings give rise to security vulnerabilities and demand hardening measures. Certificate names must be correctly mapped to the intended user account in Active Directory. A lack of strong name-based mappings allows certain weak certificate mappings, such as Issuer/Subject AltSecID and User Principal Names (UPN) mappings, to be treated as strong mappings.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Enable computer and user accounts to be trusted for delegation" user right allows the "Trusted for Delegation" setting to be changed. This could allow unauthorized users to impersonate other users.

An account that does not have Administrator duties must not have Administrator rights. Such rights would allow the account to bypass or modify required security restrictions on that machine and make it vulnerable to attack.

System administrators must log on to systems using only accounts with the minimum level of authority necessary.

For domain-joined member servers, the Domain Admins group must be replaced by a domain member server administrator group (Refer to AD.0003 in the Active Directory Domain STIG). Restricting highly privileged accounts from the local Administrators group helps mitigate the risk of privilege escalation resulting from credential theft attacks.

Standard user accounts must not be members of the built-in Administrators group.

The username is one part of logon credentials that could be used to gain access to a system. Preventing the enumeration of users limits this information to authorized personnel.

The default Windows configuration caches the last logon credentials for users who log on interactively to a system. This feature is provided for system availability reasons, such as the user's machine being disconnected from the network or domain controllers being unavailable. Even though the credential cache is well protected, if a system is attacked, an unauthorized individual may isolate the password to a domain user account using a password-cracking program and gain access to the domain.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Access this computer from the network" user right may access resources on the system, and this right must be limited to those requiring it.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Deny log on as a batch job" user right defines accounts that are prevented from logging on to the system as a batch job, such as Task Scheduler.

In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain.

The Guests group must be assigned to prevent unauthenticated access.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Deny log on locally" user right defines accounts that are prevented from logging on interactively.

In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain.

The Guests group must be assigned this right to prevent unauthenticated access.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Enable computer and user accounts to be trusted for delegation" user right allows the "Trusted for Delegation" setting to be changed. This could allow unauthorized users to impersonate other users.

To ensure secure DOD websites and DOD-signed code are properly validated, the system must trust the DOD Root CAs. The DOD root certificates will ensure that the trust chain is established for server certificates issued from the DOD CAs.

Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182, SRG-OS-000775-GPOS-00230

To ensure users do not experience denial of service when performing certificate-based authentication to DOD websites due to the system chaining to a root other than DOD Root CAs, the US DOD CCEB Interoperability Root CA cross-certificates must be installed in the Untrusted Certificate Store. This requirement only applies to unclassified systems.

Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182

An account without a password can allow unauthorized access to a system as only the username would be required. Password policies must prevent accounts with blank passwords from existing on a system. However, if a local account with a blank password does exist, enabling this setting will prevent network access, limiting the account to local console logon only.

The built-in guest account is a well-known user account on all Windows systems and, as initially installed, does not require a password. This can allow access to system resources by unauthorized users. Renaming this account to an unidentified name improves the protection of this account and the system.

Requests sent on the secure channel are authenticated, and sensitive information (such as passwords) is encrypted, but not all information is encrypted. If this policy is enabled, outgoing secure channel traffic will be encrypted and signed.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

Requests sent on the secure channel are authenticated, and sensitive information (such as passwords) is encrypted, but the channel is not integrity checked. If this policy is enabled, outgoing secure channel traffic will be signed.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

Computer account passwords are changed automatically on a regular basis. This setting controls the maximum password age that a machine account may have. This must be set to no more than 30 days, ensuring the machine changes its password monthly.

Unattended systems are susceptible to unauthorized use and must be locked when unattended. The screen saver must be set at a maximum of 15 minutes and be password protected. This protects critical and sensitive data from exposure to unauthorized personnel with physical access to the computer.

Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012

Failure to display the logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources.

Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088

The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB client will only communicate with an SMB server that performs SMB packet signing.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

Some non-Microsoft SMB servers only support unencrypted (plain-text) password authentication. Sending plain-text passwords across the network when authenticating to an SMB server reduces the overall security of the environment. Check with the vendor of the SMB server to determine if there is a way to support encrypted password authentication.

The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB server will negotiate SMB packet signing as requested by the client.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

Anonymous enumeration of SAM accounts allows anonymous logon users (null session connections) to list all accounts names, thus providing a list of potential points to attack the system.

Access by anonymous users must be restricted. If this setting is enabled, anonymous users have the same rights and permissions as the built-in Everyone group. Anonymous users must not have these permissions or rights.

Services using Local System that use Negotiate when reverting to NTLM authentication may gain unauthorized access if allowed to authenticate anonymously versus using the computer identity.

PKU2U is a peer-to-peer authentication protocol. This setting prevents online identities from authenticating to domain-joined systems. Authentication will be centrally managed with Windows user accounts.

The Kerberos v5 authentication protocol is the default for authentication of users who are logging on to domain accounts. NTLM, which is less secure, is retained in later Windows versions for compatibility with clients and servers that are running earlier versions of Windows or applications that still use it. It is also used to authenticate logons to stand-alone or nondomain-joined computers that are running later versions.

Microsoft has implemented a variety of security support providers for use with Remote Procedure Call (RPC) sessions. All of the options must be enabled to ensure the maximum security level.

If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure.

The cornerstone of the PKI is the private key used to encrypt or digitally sign information.

If the private key is stolen, this will lead to the compromise of the authentication and nonrepudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user.

Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys.

Windows systems maintain a global list of shared system resources such as DOS device names, mutexes, and semaphores. Each type of object is created with a default Discretionary Access Control List (DACL) that specifies who can access the objects with what permissions. When this policy is enabled, the default DACL is stronger, allowing nonadministrative users to read shared objects but not to modify shared objects they did not create.

User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting prevents User Interface Accessibility programs from disabling the secure desktop for elevation prompts.

UAC is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting controls the behavior of elevation when requested by a standard user account.

Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157

UAC is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures Windows to only allow applications installed in a secure location on the file system, such as the Program Files or the Windows\System32 folders, to run with elevated privileges.

UAC is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures non-UAC-compliant applications to run in virtualized file and registry entries in per-user locations, allowing them to run.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Access Credential Manager as a trusted caller" user right may be able to retrieve the credentials of other accounts from Credential Manager.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Allow log on locally" user right can log on interactively to a system.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Create a pagefile" user right can change the size of a pagefile, which could affect system performance.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Create global objects" user right can create objects that are available to all sessions, which could affect processes in other users' sessions.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Create symbolic links" user right can create pointers to other objects, which could expose the system to attack.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Force shutdown from a remote system" user right can remotely shut down a system, which could result in a denial of service.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Impersonate a client after authentication" user right allows a program to impersonate another user or account to run on their behalf. An attacker could use this to elevate privileges.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

The "Load and unload device drivers" user right allows a user to load device drivers dynamically on a system. This could be used by an attacker to install malicious code.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Manage auditing and security log" user right can manage the security log and change auditing configurations. This could be used to clear evidence of tampering.

Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000063-GPOS-00032, SRG-OS-000337-GPOS-00129

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Perform volume maintenance tasks" user right can manage volume and disk configurations. This could be used to delete volumes, resulting in data loss or a denial of service.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities.

Accounts with the "Restore files and directories" user right can circumvent file and directory permissions and could allow access to sensitive data. It could also be used to overwrite more current data.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, analyze compromises that have occurred, and detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential validation records events related to validation tests on credentials for a user account logon.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, analyze compromises that have occurred, and detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential validation records events related to validation tests on credentials for a user account logon.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, analyze compromises that have occurred, and detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential validation records events related to validation tests on credentials for a user account logon.

Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, analyze compromises that have occurred, and detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential validation records events related to validation tests on credentials for a user account logon.