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Objective ID
Severity
Discussion
medium
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.
medium
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.
Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
medium
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.
Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
medium
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 attacks.
medium
A session timeout is an action taken when a session goes idle for any reason. Rather than relying on the user to manually disconnect their session prior to going idle, the Photon operating system must be able to identify when a session has idled and take action to terminate the session.
Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000279-GPOS-00109, SRG-OS-000126-GPOS-00066
Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000279-GPOS-00109, SRG-OS-000126-GPOS-00066
medium
Automated monitoring of remote access sessions allows organizations to detect cyberattacks and ensure ongoing compliance with remote access policies by auditing connection activities.
medium
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.
Shipping sshd authentication events to syslog allows organizations to use their log aggregators to correlate forensic activities among multiple systems.
medium
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.
The INFO LogLevel is required, at least, to ensure the capturing of failed login events.
low
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session.
OpenSSH on the Photon operating system is compiled with a FIPS-validated cryptographic module. The "FipsMode" setting controls whether this module is initialized and used in FIPS 140-2 mode.
Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000393-GPOS-00173, SRG-OS-000396-GPOS-00176, SRG-OS-000250-GPOS-00093, SRG-OS-000423-GPOS-00187
OpenSSH on the Photon operating system is compiled with a FIPS-validated cryptographic module. The "FipsMode" setting controls whether this module is initialized and used in FIPS 140-2 mode.
Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000393-GPOS-00173, SRG-OS-000396-GPOS-00176, SRG-OS-000250-GPOS-00093, SRG-OS-000423-GPOS-00187
medium
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.
Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019
Audit record content must be shipped to a central location, but it must also be logged locally.
Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019
medium
To compile an accurate risk assessment and provide forensic analysis, it is essential for security personnel to know exact, unfiltered details of the event in question.
medium
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.
medium
Event outcomes can include indicators of event success or failure and event-specific results (e.g., the security state of the information system after the event occurred). They also provide a means to measure the impact of an event and help authorized personnel to determine the appropriate response.
Satisfies: 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-000445-GPOS-00199, SRG-OS-000446-GPOS-00200, SRG-OS-000461-GPOS-00205, SRG-OS-000467-GPOS-00211, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220
Satisfies: 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-000445-GPOS-00199, SRG-OS-000446-GPOS-00200, SRG-OS-000461-GPOS-00205, SRG-OS-000467-GPOS-00211, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220
medium
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.
Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000344-GPOS-00135
Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000344-GPOS-00135
medium
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.
medium
Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
medium
Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
medium
Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
medium
Without the capability to restrict the roles and individuals that 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.
medium
Audit records can be generated from various components within the information system (e.g., module or policy filter).
Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212
Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212
medium
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.
medium
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.
medium
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.
medium
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.
medium
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.
medium
A replay attack may enable an unauthorized user to gain access to the operating system. Authentication sessions between the authenticator and the operating system validating the user credentials must not be vulnerable to a replay attack.
An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message.
A privileged account is any information system account with authorizations of a privileged user.
Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators.
Satisfies: SRG-OS-000074-GPOS-00042, SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000395-GPOS-00175, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message.
A privileged account is any information system account with authorizations of a privileged user.
Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators.
Satisfies: SRG-OS-000074-GPOS-00042, SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000395-GPOS-00175, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
medium
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, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
medium
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.
medium
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 result is a password that is not changed per policy requirements.
medium
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.
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.
high
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.
Note: Photon does not support building grub changes via grub2-mkconfig.
medium
To support the requirements and principles of least functionality, the operating system must provide only essential capabilities and limit the use of modules, protocols, and/or services to only those required for the proper functioning of the product.
Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000114-GPOS-00059
Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000114-GPOS-00059
medium
To ensure accountability and prevent unauthenticated access, organizational users must be uniquely identified and authenticated to prevent potential misuse and provide for nonrepudiation.
medium
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained.
Disabling inactive accounts ensures accounts that may not have been responsibly removed are not available to attackers who may have compromised their credentials.
Disabling inactive accounts ensures accounts that may not have been responsibly removed are not available to attackers who may have compromised their credentials.
medium
A TCP SYN flood attack can cause a denial of service 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
Satisfies: SRG-OS-000142-GPOS-00071, SRG-OS-000420-GPOS-00186
medium
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 a console or console port that has been left unattended.
medium
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 a console or console port that has been left unattended.
medium
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 and can provide sensitive information to an unprivileged attacker.
medium
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 and can provide sensitive information to an unprivileged attacker.
medium
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.
medium
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.
Satisfies: SRG-OS-000239-GPOS-00089, SRG-OS-000303-GPOS-00120
Satisfies: SRG-OS-000239-GPOS-00089, SRG-OS-000303-GPOS-00120
medium
When operating system accounts are disabled, user accessibility is affected. Accounts are used for identifying individual users or operating system processes. To detect and respond to events affecting user accessibility and system processing, operating systems must audit account disabling actions.
medium
When operating system accounts are removed, user accessibility is affected. Accounts are used for identifying individual users or operating system processes. To detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions.
medium
Each process on the system carries an "auditable" flag, which indicates whether its activities can be audited. Although auditd takes care of enabling this for all processes that launch after it starts, adding the kernel argument ensures the flag is set at boot for every process on the system. This includes processes created before auditd starts.
medium
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operations on audit information.
medium
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operations on audit information.
Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
medium
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.
medium
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.
Without confidence in the integrity of the auditing system and tools, the information it provides cannot be trusted.
Without confidence in the integrity of the auditing system and tools, the information it provides cannot be trusted.
medium
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-000471-GPOS-00215
Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215
medium
Audit logs are most useful when accessible by date, rather than size. This can be accomplished through a combination of an audit log rotation cron job, setting a reasonable number of logs to keep, and configuring auditd to not rotate the logs on its own. This ensures audit logs are accessible to the information system security officer (ISSO) in the event of a central log processing failure.
medium
Audit logs are most useful when accessible by date, rather than size. This can be accomplished through a combination of an audit log rotation cron job, setting a reasonable number of logs to keep, and configuring auditd to not rotate the logs on its own. This ensures audit logs are accessible to the information system security officer (ISSO) in the event of a central log processing failure.
If another solution is not used to rotate auditd logs, auditd can be configured to rotate logs.
If another solution is not used to rotate auditd logs, auditd can be configured to rotate logs.
medium
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.
medium
Installation of any nontrusted software, patches, service packs, device drivers, or operating system components can significantly affect the overall security of the operating system. Ensuring all packages' cryptographic signatures are valid prior to installation ensures the provenance of the software and protects against malicious tampering.
medium
Installation of any nontrusted software, patches, service packs, device drivers, or operating system components can significantly affect the overall security of the operating system. Cryptographically verifying the authenticity of all software packages during installation ensures the software has not been tampered with and has been provided by a trusted vendor.
medium
Installation of any nontrusted software, patches, service packs, device drivers, or operating system components can significantly affect the overall security of the operating system. Cryptographically verifying the authenticity of all software packages during installation ensures the software has not been tampered with and has been provided by a trusted vendor.
medium
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
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
low
Privileged access contains control and configuration information and is particularly sensitive, so additional protections are necessary. This is maintained by using cryptographic mechanisms such as encryption to protect confidentiality.
Nonlocal maintenance and diagnostic activities are conducted by individuals communicating through an external network (e.g., the internet) or internal network. Local maintenance and diagnostic activities are carried out by individuals physically present at the information system or information system component and not communicating across a network connection.
This requirement applies to hardware/software diagnostic test equipment or tools. It does not cover hardware/software components that may support information system maintenance, yet are a part of the system (e.g., the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch).
The operating system can meet this requirement by leveraging a cryptographic module.
Satisfies: SRG-OS-000394-GPOS-00174, SRG-OS-000424-GPOS-00188
Nonlocal maintenance and diagnostic activities are conducted by individuals communicating through an external network (e.g., the internet) or internal network. Local maintenance and diagnostic activities are carried out by individuals physically present at the information system or information system component and not communicating across a network connection.
This requirement applies to hardware/software diagnostic test equipment or tools. It does not cover hardware/software components that may support information system maintenance, yet are a part of the system (e.g., the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch).
The operating system can meet this requirement by leveraging a cryptographic module.
Satisfies: SRG-OS-000394-GPOS-00174, SRG-OS-000424-GPOS-00188
medium
ASLR makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation.
ASLR also makes it more difficult for an attacker to know the location of existing code to repurpose it using return-oriented programming (ROP) techniques.
ASLR also makes it more difficult for an attacker to know the location of existing code to repurpose it using return-oriented programming (ROP) techniques.
medium
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.
medium
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-000458-GPOS-00203, SRG-OS-000463-GPOS-00207
Audit records can be generated from various components within the information system (e.g., module or policy filter).
Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207
medium
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-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218
Audit records can be generated from various components within the information system (e.g., module or policy filter).
Satisfies: SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218
medium
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
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
medium
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).
Audit records can be generated from various components within the information system (e.g., module or policy filter).
medium
If the operating system allows the user to select passwords based on dictionary words, this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks.
medium
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
medium
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
medium
Without setting a balance between performance and ensuring all audit events are written to disk, performance of the system may suffer or the risk of missing audit entries may be too high.
medium
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.
medium
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.
medium
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.
medium
Enabling environment processing may enable users to bypass access restrictions in some configurations and must therefore be disabled.
medium
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.
medium
If other users have access to modify user-specific Secure Shell (SSH) configuration files, they may be able to log on to the system as another user.
medium
If Kerberos is enabled through Secure Shell (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.
medium
Blank passwords are one of the first things an attacker checks for when probing a system. Even is the user somehow has a blank password on the operating system, sshd must not allow that user to log in.
medium
If compression is allowed in a Secure Shell (SSH) connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection.
medium
Providing users with feedback on the last time they logged on via Secure Shell (SSH) facilitates user recognition and reporting of unauthorized account use.
medium
Secure Shell (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.
medium
Secure Shell (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 that must also be ignored while disabling host-based authentication generally.
medium
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.
medium
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 operating system environment, this can create the risk of short-term loss of systems availability due to unintentional reboot.
medium
If the skeleton files are not protected, unauthorized personnel could change user startup parameters and possibly jeopardize user files.
medium
If the "/root" path is accessible to users other than root, unauthorized users could change the root partitions files.
medium
Local initialization files are used to configure the user's shell environment upon login. Malicious modification of these files could compromise accounts upon login.
medium
If system startup scripts are accessible to unauthorized modification, this could compromise the system on startup.
medium
If files do not have valid user and group owners, unintended access to files could occur.
medium
If cron files and folders are accessible to unauthorized users, malicious jobs may be created.
medium
If cron files and folders are accessible to unauthorized users, malicious jobs may be created.
medium
If cron files and folders are accessible to unauthorized users, malicious jobs may be created.
medium
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.
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.
medium
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
medium
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.
medium
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.
medium
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.
medium
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.
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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.
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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.
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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.
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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.
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If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
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If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
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Password complexity rules must apply to all accounts on the system, including root. Without specifying the "enforce_for_root flag", "pam_cracklib" 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.
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Boot configuration files control how the system boots, including single-user mode, auditing, log levels, etc. Improper or malicious configurations can negatively affect system security and availability.
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The "sshd_config" file contains all the configuration items for sshd. Incorrect or malicious configuration of sshd can allow unauthorized access to the system, insecure communication, limited forensic trail, etc.
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The "sysctl" configuration file specifies values for kernel parameters to be set on boot. Incorrect or malicious configuration of these parameters can have a negative effect on system security.
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The "umask" value influences the permissions assigned to files when they are created. The "umask" setting in "login.defs" controls the permissions for a new user's home directory. By setting the proper "umask", home directories will only allow the new user to read and write files there.
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Secure Shell (SSH) trust relationships enable trivial lateral spread after a host compromise and therefore must be explicitly disabled.
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Passwords must be protected at all times via strong, one-way encryption. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. If they are encrypted with a weak cipher, those passwords are much more vulnerable to offline brute-force attacks.
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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 result is a password that is not changed per policy requirements.
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While enabling Transmission Control Protocol (TCP) tunnels is a valuable function of sshd, this feature is not appropriate for use on single-purpose appliances.
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By default, sshd 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 resources and reduce the exposure any partial logon attempts may create.
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Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government because this provides assurance they have been tested and validated.
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Systemd contains an ability to set fallback DNS servers. This 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 information unknowingly in the event DNS is absent or misconfigured at the system level.