Microsoft Windows Server 2012/2012 R2 Domain Controller Security Technical Implementation Guide

Administrative accounts may perform any action on a system. Users with administrative accounts must be documented to ensure those with this level of access are clearly identified.

If SAs are assigned to systems running operating systems for which they have no training, these systems are at additional risk of unintentional misconfiguration that may result in vulnerabilities or decreased availability of the system.

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 requires administrative accounts to not access the Internet or use applications, such as email.

The policy should 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.

Technical means such as application whitelisting can be used to enforce the policy to ensure compliance.

Backup Operators are able to read and write to any file in the system, regardless of the rights assigned to it. Backup and restore rights permit users to circumvent the file access restrictions present on NTFS disk drives for backup and restore purposes. Members of the Backup Operators group must have separate logon accounts for performing backup duties.

Setting application accounts to expire may cause applications to stop functioning. However, not changing them on a regular basis exposes them to attack. If managed service accounts are used, this alleviates the need to manually change application account passwords.

Security configuration tools such as Group Policies and Security Templates allow system administrators to consolidate security-related system settings into a single configuration file. These settings can then be applied consistently to any number of Windows machines.

Operating system backup is a critical step in maintaining data assurance and availability.

User-level information is data generated by information system and/or application users.

Backups shall be consistent with organizational recovery time and recovery point objectives.

Operating system backup is a critical step in maintaining data assurance and availability.

Information system and security-related documentation contains information pertaining to system configuration and security settings.

Backups shall be consistent with organizational recovery time and recovery point objectives.

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.

Malicious software can establish a base on individual desktops and servers. Employing an automated mechanism to detect this type of software will aid in elimination of the software from the operating 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.

Disabling SMBv1 support may prevent access to file or print sharing resources with systems or devices that only support SMBv1. File shares and print services hosted on Windows Server 2003 are an example, however Windows Server 2003 is no longer a supported operating system. Some older network attached devices may only support SMBv1.

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 for some reason.

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

PowerShell 5.x supports script block logging. PowerShell 4.0 with the addition of patch KB3000850 on Windows 2012 R2 or KB3119938 on Windows 2012 adds support for script block logging.

Satisfies: SRG-OS-000042-GPOS-00021

The account lockout feature, when enabled, prevents brute-force password attacks on the system. This parameter specifies the period of time that an account will remain locked after the specified number of failed logon attempts.

The account lockout feature, when enabled, prevents brute-force password attacks on the system. This parameter specifies the period of time that must pass after failed logon attempts before the counter is reset to "0". The smaller this value is, the less effective the account lockout feature will be in protecting the local system.

The longer a password is in use, the greater the opportunity for someone to gain unauthorized knowledge of the passwords. Scheduled changing of passwords hinders the ability of unauthorized system users to crack passwords and gain access to a system.

Information systems not protected with strong password schemes (including passwords of minimum length) provide the opportunity for anyone to crack the password, thus gaining access to the system and compromising the device, information, or the local network.

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

This setting determines the maximum amount of time (in minutes) that a granted session ticket can be used to access a particular service. Session tickets are used only to authenticate new connections with servers. Ongoing operations are not interrupted if the session ticket used to authenticate the connection expires during the connection.

This setting determines the period of time (in days) during which a user's TGT may be renewed. This security configuration limits the amount of time an attacker has to crack the TGT and gain access.

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

When directory service database 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 relying on the directory service.

For Active Directory (AD), the Group Policy objects require special attention. In a distributed administration model (i.e., help desk), Group Policy objects are more likely to have access permissions changed from the secure defaults. If inappropriate access permissions are defined for Group Policy Objects, this could allow an intruder to change the security policy applied to all domain client computers (workstations and servers).

When directory service database 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.

For Active Directory (AD), the Organizational Unit (OU) objects require special attention. In a distributed administration model (i.e., help desk), OU objects are more likely to have access permissions changed from the secure defaults. If inappropriate access permissions are defined for OU objects, it could allow an intruder to add or delete users in the OU. This could result in unauthorized access to data or a Denial of Service to authorized users.

When a directory service using multi-master replication (such as AD) executes on computers that do not have synchronized time, directory data may be corrupted or updated invalidly.

The lack of synchronized time could lead to audit log data that is misleading, inconclusive, or unusable. In cases of intrusion this may invalidate the audit data as a source of forensic evidence in an incident investigation.

In AD, the lack of synchronized time could prevent clients from logging on or accessing server resources as a result of Kerberos requirements related to time variance.

Executing application servers on the same host machine with a directory server may substantially weaken the security of the directory server. Web or database server applications usually require the addition of many programs and accounts increasing the attack surface of the computer.

Some applications require the addition of privileged accounts providing potential sources of compromise. Some applications (such as MS Exchange) may require the use of network ports or services conflicting with the directory server. In this case, non-standard ports might be selected and this could interfere with intrusion detection or prevention services.

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.

To the extent that anonymous access to directory data (outside the root DSE) is permitted, read access control of the data is effectively disabled. If other means of controlling access (such as, network restrictions) are compromised, there may be nothing else to protect the confidentiality of sensitive directory data.

The krbtgt account acts as a service account for the Kerberos Key Distribution Center (KDC) service. The account and password are created when a domain is created and the password is typically not changed. If the krbtgt account is compromised, attackers can create valid Kerberos Ticket Granting Tickets (TGT).

The password must be changed twice to effectively remove the password history.Changing once, waiting for replication to complete and the amount of time equal to or greater than the maximum Kerberos ticket lifetime, and changing again reduces the risk of issues.

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.

Other Account Management Events records events such as the access of a password hash or the Password Policy Checking API being called.

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.

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.

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.

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 detecting 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.

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 detecting 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.

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.

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.

Special Logon records special logons which have administrative privileges and can be used to elevate processes.

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.

Central Access Policy Staging auditing under Object Access is used to enable the recording of events related to differences in permissions between central access policies and proposed policies.

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.

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.

Authorization Policy Change records events related to changes in user rights, such as Create a token object.

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".

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.

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-000458-GPOS-00203

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 System Extension records events related to extension code being loaded by the security subsystem.

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.

Audit records are essential for investigating system activity after the fact. Retention periods for audit data are determined based on the sensitivity of the data handled by the system.

Protection of log data includes assuring 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.

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 Active Directory (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 Group Policy objects. 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-000471-GPOS-00215

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 Active Directory (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 Infrastructure 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-000471-GPOS-00215

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 Active Directory (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 AdminSDHolder 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-000471-GPOS-00215

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 in order to make access decisions regarding the modification or deletion of audit tools.

The Responder network protocol driver allows a computer to be discovered and located on a network. Disabling this helps protect the system from potentially being discovered and connected to by unauthorized devices.

A Network Bridge can connect two or more network segments, allowing unauthorized access or exposure of sensitive data. This setting prevents a Network Bridge from being installed and configured.

Routing all Direct Access traffic through the internal network allows monitoring and prevents split tunneling.

Windows Connect Now allows the discovery and configuration of devices over wireless. Wireless devices must be managed. If a rogue device is connected to a system, there is potential for sensitive information to be compromised.

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 uncontrolled updates to the system.
This setting will prevent Windows from searching Windows Update for point and print drivers. Only the local driver store and server driver cache will be searched.

Remote access to the Plug and Play interface could potentially allow connections by unauthorized devices. This setting configures remote access to the Plug and Play interface and must be disabled.

A system restore point allows a rollback if an issue is encountered when a new device driver is installed.

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 uncontrolled updates to the system.
This setting will prevent Windows from sending an error report to Microsoft when a device driver requests additional software during installation.

Uncontrolled system updates can introduce issues to a system. Obtaining update components from an outside source may also potentially provide sensitive information outside of the enterprise. Device driver updates must be obtained from an internal source.

Compromised boot drivers can introduce malware prior to some 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.

If this setting is enabled, then Group Policy settings are not refreshed while a user is currently logged on. This could lead to instances when a user does not have the latest changes to a policy applied and is therefore operating in an insecure context.

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 uncontrolled updates to the system.
This setting prevents the computer from downloading print driver packages over HTTP.

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 uncontrolled updates to the system.
This setting prevents errors in handwriting recognition on tablet PCs from being reported to Microsoft.

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 uncontrolled updates to the system.
This setting prevents the client computer from printing over HTTP, which allows the computer to print to printers on the intranet as well as the Internet.

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 uncontrolled updates to the system.
This setting prevents Windows from searching Windows Update for device drivers when no local drivers for a device are present.

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.

Authentication must always be required when accessing a system. This setting ensures the user is prompted for a password on resume from sleep (on battery).

Remote assistance allows another user to view or take control of the local session of a user. Unsolicited remote assistance is help that is offered by the remote user. This may allow unauthorized parties access to the resources on the computer.

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. This setting will turn on session logging for Remote Assistance connections.

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 uncontrolled updates to the system.
This setting prevents the MSDT from communicating with and sending collected data to Microsoft, the default support provider.

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 uncontrolled updates to the system.
This setting prevents responsiveness events from being aggregated and sent to Microsoft.

Enabling trusted app installation allows for enterprise line of business Windows 8 type apps. A trusted app package is one that is signed with a certificate chain that can be successfully validated in the enterprise. Configuring this ensures enterprise line of business apps are accessible.

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 non-volume 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.

Visible passwords may be seen by nearby persons, compromising them. The password reveal button can be used to display an entered password and must not be allowed.

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.

Windows SmartScreen helps protect systems from programs downloaded from the Internet that may be malicious. Warning a user before running downloaded unknown software, at minimum, will help prevent potentially malicious programs from executing.

Legacy plug-in applications may continue to function when a File Explorer session has become corrupt. Disabling this feature will prevent this.

The location service on systems may allow sensitive data to be used by applications on the system. This should be turned off unless explicitly allowed for approved systems/applications.

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

Remote connections must be encrypted to prevent interception of data or sensitive information. Selecting "High Level" will ensure encryption of Remote Desktop Services sessions in both directions.

If a communal temporary folder is used for remote desktop sessions, it might be possible for users to access other users' temporary folders. If this setting is enabled, only one temporary folder is used for all remote desktop sessions. Per session temporary folders must be established.

Basic authentication uses plain text passwords that could be used to compromise a system.

Uncontrolled installation of applications can introduce various issues, including system instability, and provide access to sensitive information. Installation of applications must be controlled by the enterprise. Turning off access to the Windows Store will limit access to publicly available applications.

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.

Uncontrolled system updates can introduce issues to a system. This setting will prevent users from applying vendor-signed updates (though they may be from a trusted source).

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 uncontrolled updates to the system.
This setting prevents users from being presented with Privacy and Installation options on first use of Windows Media Player, which could enable some communication with the vendor.

Basic authentication uses plain text passwords that could be used to compromise a system.

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

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

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.

Preventing the redirection of Remote Desktop session data to a client computer's LPT ports helps reduce possible exposure of sensitive data.

Preventing the redirection of Plug and Play devices in Remote Desktop sessions helps reduce possible exposure of sensitive data.

Slide shows that are 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.

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

A known vulnerability in Windows could allow the execution of malicious code by either opening a compromised document or viewing it in the Windows Preview pane.

Organizations must disable the Windows Preview pane and Windows Detail pane.

When the WDigest Authentication protocol is enabled, plain text passwords are stored in the Local Security Authority Subsystem Service (LSASS) exposing them to theft. This setting will prevent WDigest from storing credentials in memory.

Systems at unsupported service packs or releases will not receive security updates for new vulnerabilities, which leave them subject to exploitation. Systems must be maintained at a service pack level supported by the vendor with new security updates.

The ability to set access permissions and auditing is critical to maintaining the security and proper access controls of a system. To support this, local volumes must be formatted using a file system that supports NTFS attributes.

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" (V-3377).

Allowing a system to boot into multiple operating systems (dual-booting) may allow security to be circumvented on a secure system.

Outdated or unused accounts provide penetration points that may go undetected. Inactive accounts must be deleted if no longer necessary or, if still required, disabled until needed.

Passwords that do not expire or are reused increase the exposure of a password with greater probability of being discovered or cracked.

Shares on a system provide network access. To prevent exposing sensitive information, where shares are necessary, permissions must be reconfigured to give the minimum access to those accounts that require it.

Unnecessary services increase the attack surface of a system. Some services may be run under the local System account, which generally has more permissions than required by the service. Compromising a service could allow an intruder to obtain system permissions and open the system to a variety of attacks.

Without the use of automated mechanisms to scan for security flaws on a continuous and/or periodic basis, the operating system or other system components may remain vulnerable to the exploits presented by undetected software flaws. The operating system may have an integrated solution incorporating continuous scanning using ESS and periodic scanning using other tools..

Failure to verify a certificate's revocation status can result in the system accepting a revoked, and therefore unauthorized, certificate. This could result in the installation of unauthorized software or a connection for rogue networks, depending on the use for which the certificate is intended. Querying for certificate revocation mitigates the risk that the system will accept an unauthorized certificate.

The FTP service allows remote users to access shared files and directories. Access outside of the specific directories of shared data could provide access to system resources and compromise the system.

Emergency administrator accounts are privileged accounts which are 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 should 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.

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 DoD Interoperability Root CA cross-certificates must be installed in the Untrusted Certificate Store. This requirement only applies to unclassified systems.

Domain controller 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.

Permissions on the Winlogon registry key must only allow privileged accounts to change registry values. If standard users have these permissions, there is a potential for programs to run with elevated privileges when a privileged user logs on to the system.

The registry is integral to the function, security, and stability of the Windows system. Some processes may require anonymous access to the registry. This must be limited to properly protect the system.

An account without a password can allow unauthorized access to a system as only the username would be required. Password policies should prevent accounts with blank passwords from existing on a system. However, if a local account with a blank password did 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.

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.
This setting prevents the system from generating audit events for every file backed up or restored, which could fill the security log in Windows, making it difficult to identify actual issues.

Removable hard drives, if they are not properly configured, can be formatted and ejected by users who are not members of the Administrators Group. Formatting and ejecting removable NTFS media must only be done by administrators.

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.

Computer account passwords are changed automatically on a regular basis. Disabling automatic password changes can make the system more vulnerable to malicious access. Frequent password changes can be a significant safeguard for your system. A new password for the computer account will be generated every 30 days.

A computer connecting to a domain controller will establish a secure channel. Requiring strong session keys enforces 128-bit encryption between systems.

Disabling the Ctrl+Alt+Del security attention sequence can compromise system security. Because only Windows responds to the Ctrl+Alt+Del security sequence, a user can be assured that any passwords entered following that sequence are sent only to Windows. If the sequence requirement is eliminated, malicious programs can request and receive a user's Windows password. Disabling this sequence also suppresses a custom logon banner.

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

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.

Unattended systems are susceptible to unauthorized use and must be locked. Configuring a system to lock when a smart card is removed will ensure the system is inaccessible when unattended.

The server message block (SMB) protocol provides the basis for many network operations. If this policy is enabled, the SMB client will request packet signing when communicating with an SMB server that is enabled or required to perform SMB packet signing.

Open sessions can increase the avenues of attack on a system. This setting is used to control when a computer disconnects an inactive SMB session. If client activity resumes, the session is automatically reestablished. This protects critical and sensitive network data from exposure to unauthorized personnel with physical access to the computer.

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.

If a service principle name (SPN) is provided by the client, it is validated against the server's list of SPNs. Implementation may disrupt file and print sharing capabilities.

Configuring the system to disable IPv6 source routing protects against spoofing.

Allowing ICMP redirect of routes can lead to traffic not being routed properly. When disabled, this forces ICMP to be routed via shortest path first.

IPSec exemption filters allow specific traffic that may be needed by the system for such things as Kerberos authentication. This setting configures Windows for specific IPSec exemptions.

The Internet Router Discovery Protocol (IRDP) is used to detect and configure default gateway addresses on the computer. If a router is impersonated on a network, traffic could be routed through the compromised system.

Allowing more than several seconds makes the computer vulnerable to a potential attack from someone walking up to the console to attempt to log on to the system before the lock takes effect.

In a SYN flood attack, the attacker sends a continuous stream of SYN packets to a server, and the server leaves the half-open connections open until it is overwhelmed and is no longer able to respond to legitimate requests.

Allowing anonymous SID/Name translation can provide sensitive information for accessing a system. Only authorized users must be able to perform such translations.

Allowing anonymous logon users (null session connections) to list all account names and enumerate all shared resources can provide a map of potential points to attack the system.

Named pipes that can be accessed anonymously provide the potential for gaining unauthorized system access. Pipes are internal system communications processes. They are identified internally by ID numbers that vary between systems. To make access to these processes easier, these pipes are given names that do not vary between systems. This setting controls which of these pipes anonymous users may access.

The registry is integral to the function, security, and stability of the Windows system. Some processes may require remote access to the registry. This setting controls which registry paths and sub-paths are accessible from a remote computer. These registry paths must be limited, as they could give unauthorized individuals access to the registry.

Anonymous access to network shares provides the potential for gaining unauthorized system access by network users. This could lead to the exposure or corruption of sensitive data.

Services using Local System that use Negotiate when reverting to NTLM authentication may gain unauthorized access if allowed to authenticate anonymously vs. 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 LAN Manager hash uses a weak encryption algorithm and there are several tools available that use this hash to retrieve account passwords. This setting controls whether or not a LAN Manager hash of the password is stored in the SAM the next time the password is changed.

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 computers that are running later versions.

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

Displaying the shutdown button may allow individuals to shut down a system anonymously. Only authenticated users should be allowed to shut down the system. Preventing display of this button in the logon dialog box ensures that individuals who shut down the system are authorized and tracked in the system's Security event log.

This setting controls the behavior of non-Windows subsystems when dealing with the case of arguments or commands. Case sensitivity could lead to the access of files or commands that must be restricted. To prevent this from happening, case insensitivity restrictions must be required.

User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures the built-in Administrator account so that it runs in Admin Approval Mode.

Satisfies: SRG-OS-000373-GPOS-00158

User Account Control (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-00158

User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures whether Windows elevates all applications, or only signed ones.

User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting enables UAC.

Satisfies: SRG-OS-000373-GPOS-00158

User Account Control (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.

The POSIX subsystem is an Institute of Electrical and Electronic Engineers (IEEE) standard that defines a set of operating system services. The POSIX Subsystem is required if the server supports applications that use that subsystem. The subsystem introduces a security risk relating to processes that can potentially persist across logins. That is, if a user starts a process and then logs out, there is a potential that the next user who logs in to the system could access the previous users process. This is dangerous because the process started by the first user may retain that users system privileges, and anything the second user does with that process will be performed with the privileges of the first user.

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. You can lower the risk of an attacker pulling this off in a corporate network by implementing strong physical security measures to protect the network infrastructure. Furthermore, implementing Internet Protocol security (IPSec) authentication header mode (AH), which performs mutual authentication and packet integrity for Internet Protocol (IP) traffic, can make all types of man in the middle attacks extremely difficult.

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 non-repudiation 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.

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

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

The automatic start of the Smart Card Removal Policy service is required to support the smart card removal behavior requirement.

Unattended systems are susceptible to unauthorized use and must be locked when unattended. Enabling a password-protected screen saver to engage after a specified period of time helps protects critical and sensitive data from exposure to unauthorized personnel with physical access to the computer.

Toast notifications that are 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.

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 uncontrolled updates to the system.
This setting ensures users cannot provide ratings feedback to Microsoft for Help content.

Preserving zone of origin (internet, intranet, local, restricted) information on file attachments allows Windows to determine risk. This setting prevents users from manually removing zone information from saved file attachments.

Allowing users to share files in their profiles may provide unauthorized access or result in the exposure of sensitive data.

Inappropriate granting of user rights can provide 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.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Act as part of the operating system" user right can assume the identity of any user and gain access to resources that user is authorized to access. Any accounts with this right can take complete control of a system.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Back up files and directories" user right can circumvent file and directory permissions and could allow access to sensitive data.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

The "Create a token object" user right allows a process to create an access token. This could be used to provide elevated rights and compromise a system.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Create permanent shared objects" user right could expose sensitive data by creating shared objects.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Debug programs" user right can attach a debugger to any process or to the kernel, providing complete access to sensitive and critical operating system components. This right is given to Administrators in the default configuration.

Inappropriate granting of user rights can provide 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.

Inappropriate granting of user rights can provide 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.

Inappropriate granting of user rights can provide 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 potentially allow unauthorized users to impersonate other users.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

The "Generate security audits" user right specifies users and processes that can generate Security Log audit records, which must only be the system service accounts defined.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Increase scheduling priority" user right can change a scheduling priority causing performance issues or a DoS.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

The "Lock pages in memory" user right allows physical memory to be assigned to processes, which could cause performance issues or a DoS.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Modify firmware environment values" user right can change hardware configuration environment variables. This could result in hardware failures or a DoS.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Profile single process" user right can monitor nonsystem processes performance. An attacker could potentially use this to identify processes to attack.

Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities.

Accounts with the "Take ownership of files or other objects" user right can take ownership of objects and make changes.

Inappropriate granting of user rights can provide 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.