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XCCDF
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide
An XCCDF Benchmark
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File Metadata
104 rules organized in 104 groups
SRG-OS-000004-GPOS-00004
1 Rule
The Photon operating system must audit all account creations.
Medium Severity
Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to create an account. Auditing account creation actions provides logging that can be used for forensic purposes. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000476-GPOS-00221
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000023-GPOS-00006
1 Rule
The Photon operating system must display the Standard Mandatory DOD Notice and Consent Banner before granting local or remote access to the system.
Medium Severity
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DOD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
SRG-OS-000027-GPOS-00008
1 Rule
The Photon operating system must limit the number of concurrent sessions to ten for all accounts and/or account types.
Low Severity
Operating system management includes the ability to control the number of users and user sessions that utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to Denial of Service (DoS) attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system.
SRG-OS-000032-GPOS-00013
1 Rule
The Photon operating system must monitor remote access logins.
Medium Severity
Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyberattacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).
SRG-OS-000033-GPOS-00014
1 Rule
The Photon operating system must have the OpenSSL FIPS provider installed to protect the confidentiality of remote access sessions.
High Severity
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. OpenSSH on the Photon operating system when configured appropriately can utilize a FIPS validated OpenSSL for cryptographic operations. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000423-GPOS-00187, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
SRG-OS-000037-GPOS-00015
1 Rule
The Photon operating system must configure auditd to log to disk.
Medium Severity
Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content must be shipped to a central location, but it must also be logged locally.
SRG-OS-000039-GPOS-00017
1 Rule
The Photon operating system must enable the auditd service.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. To that end, the auditd service must be configured to start automatically and be running at all times. Satisfies: SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000062-GPOS-00031, SRG-OS-000255-GPOS-00096, SRG-OS-000363-GPOS-00150, SRG-OS-000365-GPOS-00152, SRG-OS-000446-GPOS-00200
SRG-OS-000042-GPOS-00020
1 Rule
The Photon operating system must be configured to audit the execution of privileged functions.
Medium Severity
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing all actions by superusers is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000326-GPOS-00126
SRG-OS-000046-GPOS-00022
1 Rule
The Photon operating system must alert the ISSO and SA in the event of an audit processing failure.
Medium Severity
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000344-GPOS-00135
SRG-OS-000057-GPOS-00027
1 Rule
The Photon operating system must protect audit logs from unauthorized access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
SRG-OS-000063-GPOS-00032
1 Rule
The Photon operating system must allow only authorized users to configure the auditd service.
Medium Severity
Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
SRG-OS-000064-GPOS-00033
1 Rule
The Photon operating system must generate audit records when successful/unsuccessful attempts to access privileges occur.
Medium Severity
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000474-GPOS-00219
SRG-OS-000069-GPOS-00037
1 Rule
The Photon operating system must enforce password complexity by requiring that at least one uppercase character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000070-GPOS-00038
1 Rule
The Photon operating system must enforce password complexity by requiring that at least one lowercase character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000071-GPOS-00039
1 Rule
The Photon operating system must enforce password complexity by requiring that at least one numeric character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000072-GPOS-00040
1 Rule
The Photon operating system must require the change of at least eight characters when passwords are changed.
Medium Severity
If the operating system allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. If the password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters.
SRG-OS-000073-GPOS-00041
1 Rule
The operating system must store only encrypted representations of passwords.
High Severity
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.
SRG-OS-000074-GPOS-00042
1 Rule
The Photon operating system must not have the telnet package installed.
High Severity
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.
SRG-OS-000075-GPOS-00043
1 Rule
The Photon operating system must enforce one day as the minimum password lifetime.
Medium Severity
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
SRG-OS-000076-GPOS-00044
1 Rule
The Photon operating systems must enforce a 90-day maximum password lifetime restriction.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
SRG-OS-000077-GPOS-00045
1 Rule
The Photon operating system must prohibit password reuse for a minimum of five generations.
Medium Severity
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements.
SRG-OS-000078-GPOS-00046
1 Rule
The Photon operating system must enforce a minimum 15-character password length.
Medium Severity
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
SRG-OS-000080-GPOS-00048
1 Rule
The Photon operating system must require authentication upon booting into single-user and maintenance modes.
Medium Severity
If the system does not require authentication before it boots into single-user mode, anyone with console access to the system can trivially access all files on the system. GRUB2 is the boot loader for Photon OS and can be configured to require a password to boot into single-user mode or make modifications to the boot menu. Note: Photon does not support building grub changes via grub2-mkconfig.
SRG-OS-000095-GPOS-00049
1 Rule
The Photon operating system must disable unnecessary kernel modules.
Medium Severity
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of nonessential capabilities include, but are not limited to, games, software packages, tools, and demonstration software, not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. Satisfies: SRG-OS-000095-GPOS-00049, SRG-OS-000114-GPOS-00059
SRG-OS-000104-GPOS-00051
1 Rule
The Photon operating system must not have duplicate User IDs (UIDs).
Medium Severity
To ensure accountability and prevent unauthenticated access, organizational users must be uniquely identified and authenticated to prevent potential misuse and provide for nonrepudiation.
SRG-OS-000120-GPOS-00061
1 Rule
The Photon operating system must use mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module.
Medium Severity
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DOD data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system.
SRG-OS-000138-GPOS-00069
1 Rule
The Photon operating system must restrict access to the kernel message buffer.
Medium Severity
Restricting access to the kernel message buffer limits access only to root. This prevents attackers from gaining additional system information as a nonprivileged user.
SRG-OS-000142-GPOS-00071
1 Rule
The Photon operating system must be configured to use TCP syncookies.
Medium Severity
A TCP SYN flood attack can cause a Denial of Service (DOS) by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected and enables the system to continue servicing valid connection requests. Satisfies: SRG-OS-000142-GPOS-00071, SRG-OS-000420-GPOS-00186
SRG-OS-000163-GPOS-00072
1 Rule
The Photon operating system must terminate idle Secure Shell (SSH) sessions after 15 minutes.
Medium Severity
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, deallocating associated TCP/IP address/port pairs at the operating system level, and deallocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. Satisfies: SRG-OS-000163-GPOS-00072, SRG-OS-000395-GPOS-00175
SRG-OS-000205-GPOS-00083
1 Rule
The Photon operating system /var/log directory must be restricted.
Medium Severity
Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers.
SRG-OS-000206-GPOS-00084
1 Rule
The Photon operating system must reveal error messages only to authorized users.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives.
SRG-OS-000239-GPOS-00089
1 Rule
The Photon operating system must audit all account modifications.
Medium Severity
Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to modify an existing account. Auditing account modification actions provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.
SRG-OS-000241-GPOS-00091
1 Rule
The Photon operating system must audit all account removal actions.
Medium Severity
When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes.
SRG-OS-000250-GPOS-00093
1 Rule
The Photon operating system must implement only approved ciphers to protect the integrity of remote access sessions.
High Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash.
SRG-OS-000254-GPOS-00095
1 Rule
The Photon operating system must initiate session audits at system startup.
Medium Severity
If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created.
SRG-OS-000256-GPOS-00097
1 Rule
The Photon operating system must protect audit tools from unauthorized access.
Medium Severity
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 access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
SRG-OS-000266-GPOS-00101
1 Rule
The Photon operating system must enforce password complexity by requiring that at least one special character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity or strength is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor in determining how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Special characters are those characters that are not alphanumeric. Examples include: ~ ! @ # $ % ^ *.
SRG-OS-000278-GPOS-00108
1 Rule
The Photon operating system must use cryptographic mechanisms to protect the integrity of audit tools.
High Severity
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools with the purpose of providing the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed in order to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
SRG-OS-000279-GPOS-00109
1 Rule
The operating system must automatically terminate a user session after inactivity time-outs have expired.
Medium Severity
Automatic session termination addresses the termination of user-initiated logical sessions in contrast to the termination of network connections that are associated with communications sessions (i.e., network disconnect). A logical session (for local, network, and remote access) is initiated whenever a user (or process acting on behalf of a user) accesses an organizational information system. Such user sessions can be terminated (and thus terminate user access) without terminating network sessions. Session termination terminates all processes associated with a user's logical session except those processes that are specifically created by the user (i.e., session owner) to continue after the session is terminated. Conditions or trigger events requiring automatic session termination can include, for example, organization-defined periods of user inactivity, targeted responses to certain types of incidents, and time-of-day restrictions on information system use. This capability is typically reserved for specific operating system functionality where the system owner, data owner, or organization requires additional assurance. Satisfies: SRG-OS-000279-GPOS-00109, SRG-OS-000126-GPOS-00066
SRG-OS-000324-GPOS-00125
1 Rule
The Photon operating system must enable symlink access control protection in the kernel.
High Severity
By enabling the fs.protected_symlinks kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the UID of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().
SRG-OS-000327-GPOS-00127
1 Rule
The Photon operating system must audit the execution of privileged functions.
Medium Severity
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000240-GPOS-00090, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000471-GPOS-00215
SRG-OS-000329-GPOS-00128
1 Rule
The Photon operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes occur.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.
SRG-OS-000341-GPOS-00132
1 Rule
The Photon operating system must allocate audit record storage capacity to store audit records when audit records are not immediately sent to a central audit record storage facility.
Low Severity
Audit logs are most useful when accessible by date, rather than size. This can be accomplished through a combination of an audit log rotation and setting a reasonable number of logs to keep. This ensures that audit logs are accessible to the ISSO in the event of a central log processing failure.
SRG-OS-000343-GPOS-00134
1 Rule
The Photon operating system must immediately notify the SA and ISSO when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
Low Severity
If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000366-GPOS-00153
1 Rule
The Photon operating system TDNF package management tool must cryptographically verify the authenticity of all software packages during installation.
High Severity
Installation of any nontrusted software, patches, service packs, device drivers, or operating system components can significantly affect the overall security of the operating system. This requirement ensures the software has not been tampered with and has been provided by a trusted vendor.
SRG-OS-000373-GPOS-00156
1 Rule
The Photon operating system must require users to reauthenticate for privilege escalation.
Medium Severity
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
SRG-OS-000433-GPOS-00193
1 Rule
The Photon operating system must implement address space layout randomization to protect its memory from unauthorized code execution.
Medium Severity
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks.
SRG-OS-000437-GPOS-00194
1 Rule
The Photon operating system must remove all software components after updated versions have been installed.
Medium Severity
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.
SRG-OS-000470-GPOS-00214
1 Rule
The Photon operating system must generate audit records when successful/unsuccessful logon attempts occur.
Medium Severity
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000471-GPOS-00216
1 Rule
The Photon operating system must be configured to audit the loading and unloading of dynamic kernel modules.
Medium Severity
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000478-GPOS-00223
1 Rule
The Photon operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.
High Severity
Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. Satisfies: SRG-OS-000478-GPOS-00223, SRG-OS-000396-GPOS-00176
SRG-OS-000480-GPOS-00225
1 Rule
The Photon operating system must prevent the use of dictionary words for passwords.
Medium Severity
If the operating system allows the user to select passwords based on dictionary words, then this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks.
SRG-OS-000480-GPOS-00226
1 Rule
The Photon operating system must enforce a delay of at least four seconds between logon prompts following a failed logon attempt in login.defs.
Medium Severity
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must ensure audit events are flushed to disk at proper intervals.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. To that end, the auditd service must be configured to start automatically and be running at all times.
SRG-OS-000480-GPOS-00228
1 Rule
The Photon operating system must define default permissions for all authenticated users in such a way that the user can only read and modify their own files.
Medium Severity
Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access.
SRG-OS-000480-GPOS-00229
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disallow HostbasedAuthentication.
High Severity
SSH trust relationships enable trivial lateral spread after a host compromise and therefore must be explicitly disabled.
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must be configured to use the pam_faillock.so module.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. This module maintains a list of failed authentication attempts per user during a specified interval and locks the account in case there were more than deny consecutive failed authentications.
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must prevent leaking information of the existence of a user account.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. If the pam_faillock.so module is not configured to use the silent flag it could leak information about the existence or nonexistence of a user account.
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must audit logon attempts for unknown users.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must include root when automatically locking an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. Unless specified the root account is not included in the default faillock module options and should be included.
SRG-OS-000021-GPOS-00005
1 Rule
The Photon operating system must persist lockouts between system reboots.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. By default, account lockout information is stored under /var/run/faillock and is not persistent between reboots.
SRG-OS-000069-GPOS-00037
1 Rule
The Photon operating system must be configured to use the pam_pwquality.so module.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000366-GPOS-00153
1 Rule
The Photon operating system TDNF package management tool must cryptographically verify the authenticity of all software packages during installation for all repos.
High Severity
Installation of any nontrusted software, patches, service packs, device drivers, or operating system components can significantly affect the overall security of the operating system. This requirement ensures the software has not been tampered with and has been provided by a trusted vendor.
SRG-OS-000032-GPOS-00013
1 Rule
The Photon operating system must configure the Secure Shell (SSH) SyslogFacility.
Medium Severity
Automated monitoring of remote access sessions allows organizations to detect cyberattacks and ensure ongoing compliance with remote access policies by auditing connection activities. Shipping sshd authentication events to syslog allows organizations to use their log aggregators to correlate forensic activities among multiple systems.
SRG-OS-000032-GPOS-00013
1 Rule
The Photon operating system must enable Secure Shell (SSH) authentication logging.
Medium Severity
Automated monitoring of remote access sessions allows organizations to detect cyberattacks and ensure ongoing compliance with remote access policies by auditing connection activities. The INFO LogLevel is required, at least, to ensure the capturing of failed login events.
SRG-OS-000163-GPOS-00072
1 Rule
The Photon operating system must terminate idle Secure Shell (SSH) sessions.
Medium Severity
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, deallocating associated TCP/IP address/port pairs at the operating system level, and deallocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session.
SRG-OS-000239-GPOS-00089
1 Rule
The Photon operating system must audit all account modifications.
Medium Severity
Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to modify an existing account. Auditing account modification actions provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. Satisfies: SRG-OS-000239-GPOS-00089, SRG-OS-000303-GPOS-00120, SRG-OS-000467-GPOS-00211
SRG-OS-000480-GPOS-00226
1 Rule
The Photon operating system must enforce a delay of at least four seconds between logon prompts following a failed logon attempt.
Medium Severity
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
SRG-OS-000480-GPOS-00229
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disallow authentication with an empty password.
High Severity
Blank passwords are one of the first things an attacker checks for when probing a system. Even if the user somehow has a blank password on the OS, SSH must not allow that user to log in.
SRG-OS-000480-GPOS-00229
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disable user environment processing.
High Severity
Enabling user environment processing may enable users to bypass access restrictions in some configurations and must therefore be disabled.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must create a home directory for all new local interactive user accounts.
Medium Severity
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must disable the debug-shell service.
Medium Severity
The debug-shell service is intended to diagnose systemd related boot issues with various systemctl commands. Once enabled and following a system reboot, the root shell will be available on tty9. This service must remain disabled until and unless otherwise directed by VMware support.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disallow Generic Security Service Application Program Interface (GSSAPI) authentication.
Medium Severity
GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through Secure Shell (SSH) exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disable X11 forwarding.
Medium Severity
X11 is an older, insecure graphics forwarding protocol. It is not used by Photon and should be disabled as a general best practice to limit attack surface area and communication channels.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to perform strict mode checking of home directory configuration files.
Medium Severity
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disallow Kerberos authentication.
Medium Severity
If Kerberos is enabled through SSH, sshd provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to disallow compression of the encrypted session stream.
Medium Severity
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to display the last login immediately after authentication.
Medium Severity
Providing users with feedback on the last time they logged on via SSH facilitates user recognition and reporting of unauthorized account use.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to ignore user-specific trusted hosts lists.
Medium Severity
SSH trust relationships enable trivial lateral spread after a host compromise and therefore must be explicitly disabled. Individual users can have a local list of trusted remote machines, which must also be ignored while disabling host-based authentication generally.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to ignore user-specific known_host files.
Medium Severity
SSH trust relationships enable trivial lateral spread after a host compromise and therefore must be explicitly disabled. Individual users can have a local list of trusted remote machines, which must also be ignored while disabling host-based authentication generally.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to limit the number of allowed login attempts per connection.
Medium Severity
By setting the login attempt limit to a low value, an attacker will be forced to reconnect frequently, which severely limits the speed and effectiveness of brute-force attacks.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to restrict AllowTcpForwarding.
Medium Severity
While enabling TCP tunnels is a valuable function of sshd, this feature is not appropriate for use on single purpose appliances.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must configure Secure Shell (SSH) to restrict LoginGraceTime.
Medium Severity
By default, SSH unauthenticated connections are left open for two minutes before being closed. This setting is too permissive as no legitimate login would need such an amount of time to complete a login. Quickly terminating idle or incomplete login attempts will free up resources and reduce the exposure any partial logon attempts may create.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must be configured so that the x86 Ctrl-Alt-Delete key sequence is disabled on the command line.
Medium Severity
When the Ctrl-Alt-Del target is enabled, a locally logged-on user who presses Ctrl-Alt-Delete, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of systems availability due to unintentional reboot.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must not forward IPv4 or IPv6 source-routed packets.
Medium Severity
Source routing is an Internet Protocol mechanism that allows an IP packet to carry information, a list of addresses, that tells a router the path the packet must take. There is also an option to record the hops as the route is traversed. The list of hops taken, the "route record", provides the destination with a return path to the source. This allows the source (the sending host) to specify the route, loosely or strictly, ignoring the routing tables of some or all of the routers. It can allow a user to redirect network traffic for malicious purposes and should therefore be disabled.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must not respond to IPv4 Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.
Medium Severity
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must prevent IPv4 Internet Control Message Protocol (ICMP) redirect messages from being accepted.
Medium Severity
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must prevent IPv4 Internet Control Message Protocol (ICMP) secure redirect messages from being accepted.
Medium Severity
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must not send IPv4 Internet Control Message Protocol (ICMP) redirects.
Medium Severity
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table, possibly revealing portions of the network topology.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must log IPv4 packets with impossible addresses.
Medium Severity
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must use a reverse-path filter for IPv4 network traffic.
Medium Severity
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems that are routers for complicated networks but is helpful for end hosts and routers serving small networks.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must not perform IPv4 packet forwarding.
Medium Severity
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must send TCP timestamps.
Medium Severity
TCP timestamps are used to provide protection against wrapped sequence numbers. It is possible to calculate system uptime (and boot time) by analyzing TCP timestamps. These calculated uptimes can help a bad actor in determining likely patch levels for vulnerabilities.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must be configured to protect the Secure Shell (SSH) public host key from unauthorized modification.
Medium Severity
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must be configured to protect the Secure Shell (SSH) private host key from unauthorized access.
Medium Severity
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must enforce password complexity on the root account.
Medium Severity
Password complexity rules must apply to all accounts on the system, including root. Without specifying the enforce_for_root flag, pam_pwquality does not apply complexity rules to the root user. While root users can find ways around this requirement, given its superuser power, it is necessary to attempt to force compliance.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must disable systemd fallback DNS.
Medium Severity
Systemd contains an ability to set fallback DNS servers, which is used for DNS lookups in the event no system level DNS servers are configured or other DNS servers are specified in the Systemd resolved.conf file. If uncommented, this configuration contains Google DNS servers by default and could result in DNS leaking info unknowingly in the event DNS is absent or misconfigured at the system level.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must generate audit records for all access and modifications to the opasswd file.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
SRG-OS-000250-GPOS-00093
1 Rule
The Photon operating system must implement only approved Message Authentication Codes (MACs) to protect the integrity of remote access sessions.
High Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must enable the rsyslog service.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity.
SRG-OS-000077-GPOS-00045
1 Rule
The Photon operating system must be configured to use the pam_pwhistory.so module.
Medium Severity
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements.
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must enable hardlink access control protection in the kernel.
Medium Severity
By enabling the fs.protected_hardlinks kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().
SRG-OS-000480-GPOS-00227
1 Rule
The Photon operating system must restrict core dumps.
Medium Severity
By enabling the fs.suid_dumpable kernel parameter, core dumps are not generated for setuid or otherwise protected/tainted binaries. This prevents users from potentially accessing core dumps with privileged information they would otherwise not have access to read.