What changed in Oracle Linux 9 STIG V1R7V1R7 changes

Discussion

To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DODDoW-approved PKIs, all DODDoW systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. This requirement prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.

V-271441 in V1R7

Discussion

To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DODDoW-approved PKIs, all DODDoW systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. This requirement prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.

V-271442 in V1R7

Discussion

This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with OL 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DODDoW requirements for wireless data transmission and be approved for use by the authorizing official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the OL 9 operating system. Satisfies: SRG-OS-000095-GPOS-00049, SRG-OS-000300-GPOS-00118

V-271449 in V1R7

Title

OL 9 must display the Standard Mandatory DODoW Notice and Consent Banner before granting local or remote access to the system via a command line user logon.

Check text

Verify that OL 9 displays the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the operating system via a command line user logon. Check that a banner is displayed at the command line login screen with the following command: $ cat /etc/issue If the banner is set correctly it will return the following text: "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." If the banner text does not match the Standard Mandatory DODDoW Notice and Consent Banner exactly, or the line is commented out, this is a finding.

Fix text

Configure OL 9 to display the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the system via command line logon. Edit the "/etc/issue" file to replace the default text with the Standard Mandatory DODDoW Notice and Consent Banner. The DODDoW-required text is: "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."

V-271455 in V1R7

Discussion

Firewalld provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DODDoW 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. OL 9 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00232

V-271469 in V1R7

Discussion

Firewalld provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DODDoW 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. OL 9 functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115

V-271470 in V1R7

Discussion

Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DODDoW data. OL 9 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be used to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection.

V-271473 in V1R7

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DODDoW 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. OL 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.

V-271485 in V1R7

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DODDoW 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. OL 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.

V-271486 in V1R7

Title

OL 9 must display the Standard Mandatory DODoW Notice and Consent Banner before granting local or remote access to the system via a SSH logon.

Check text

Verify that OL 9 displays the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the system via SSH connections. Check for the location of the banner file currently being used with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '1r' | tr '1n' ' ' | xargs sudo grep -iH '^1s*banner' banner /etc/issue If the line is commented out or if the file is missing, this is a finding.

Fix text

Configure OL 9 to display the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the system via ssh. Edit the "etc/ssh/sshd_config" file or a file in "/etc/ssh/sshd_config.d" to uncomment the banner keyword and configure it to point to a file that will contain the logon banner (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor). An example configuration line is: Banner /etc/issue

V-271487 in V1R7

Title

OL 9 SSH client must be configured to use only DODDoW-approved encryption ciphers employing FIPS 140-3 validated cryptographic hash algorithms to protect the confidentiality of SSH client connections.

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DODDoW 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. OL 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.

V-271489 in V1R7

Title

OL 9 SSH client must be configured to use only DODDoW-approved Message Authentication Codes (MACs) employing FIPS 140-3 validated cryptographic hash algorithms to protect the confidentiality of SSH client connections.

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DODDoW 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. OL 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.

V-271490 in V1R7

Discussion

Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. The DODDoW common access card (CAC) with DODDoW-approved PKI is an example of multifactor authentication. Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000375-GPOS-00160, SRG-OS-000376-GPOS-00161, SRG-OS-000377-GPOS-00162

V-271491 in V1R7

Discussion

Using an authentication device, such as a common access card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DODDoW Common Access CardCAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DODDoW 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. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). Satisfies: SRG-OS-000705-GPOS-00150, SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000375-GPOS-00160

V-271493 in V1R7

Discussion

Using an authentication device, such as a common access card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DODDoW Common Access CardCAC. A privileged account is defined as an information system account with authorizations of a privileged user. Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. Factors include: 1) Something a user knows (e.g., password/PIN); 2) Something a user has (e.g., cryptographic identification device, token); and 3) Something a user is (e.g., biometric). A privileged account is defined as an information system account with authorizations of a privileged user. Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the internet). The DODDoW common access card (CAC) with DODDoW-approved PKI is an example of multifactor authentication. Satisfies: SRG-OS-000705-GPOS-00150, SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000375-GPOS-00161

V-271494 in V1R7

Discussion

The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. The DODDoW has mandated the use of the Commoncommon Accessaccess Cardcard (CAC) to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000376-GPOS-00161

V-271515 in V1R7

Check text

Verify that OL 9 is configured so that Advanced Intrusion Detection Environment (AIDE) uses cryptographic mechanisms to protect the integrity of the audit tools. Check the selection lines to ensure AIDE is configured to add/check with the following command: $ sudo catgrep -H -E '^/usr/sbin/(auditctl|auditd|ausearch|aureport|autrace|rsyslogd|augenrules)' /etc/aide.conf | grep /usretc/sbinaide/auaide.conf.d/* /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/augenrulesrsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /etc/aide/aide.conf.d/90-stig_audit_tools:/usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If AIDE is not installed, ask the system administrator (SA) how file integrity checks are performed on the system. If any of the audit tools listed above do not have a corresponding line, ask the SA to indicate what cryptographic mechanisms are being used to protect the integrity of the audit tools. If there is no evidence of integrity protection, this is a finding.

Fix text

Configure OL 9 to use cryptographic mechanisms to protect the integrity of the audit tools. AddCreate ora updatededicated configuration directory for custom security rules if it does not already exist: $ sudo mkdir -p /etc/aide/aide.conf.d Ensure the followingmain linesconfiguration file (/etc/aide.conf) is configured to include files from this directory. Edit "/etc/aide.conf" and verify the following line exists at the bottom of the file: @@include /etc/aide/aide.conf.d/90-stig_audit_tools Create the dedicated audit tools configuration file: $ sudo vi /etc/aide/aide.conf.d/90-stig_audit_tools Populate the file with the following configuration rules: # Audit Tools /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If any of the audit tools listed above are already defined inside the main "/etc/aide.conf" file, comment those lines out to prevent duplicate definition conflicts. Initialize the updated baseline database and promote it to production: $ sudo aide --init Rename the new database: $ sudo cp -p /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

V-271569 in V1R7

Check text

Verify that OL 9 sets files in directoriesthe "directory /etc/audit/rules.d/" and "/etc/audit/auditd.conf" files to have a mode of "0600" or less permissive with the following command: $ sudo statfind -c "%a %n" /etc/audit/rules.d/ -type f -name "*.rules $" sudo sh -cexec 'stat -c "%a %n" {} 1; 600 /etc/audit/rules.d/*audit.rules' 600 Verify that the files /etc/audit/rulesaudit.drules and /etc/audit/auditd.rulesconf have a mode of 0600 or less permissive with the following command: If$ thesudo filesstat in-c the"%a %n" /etc/audit/audit.rules /etc/audit/auditd.dconf 600 /"etc/audit/audit.rules 600 directory or the "/etc/audit/auditd.conf" If fileany of the audit configuration files have a mode more permissive than "0600", this is a finding.

Fix text

Configure the rules files in the directory "/etc/audit/rules.d/", the /etc/audit/audit.rules file, and the "/etc/audit/auditd.conf" file to have a mode of "0600" with the following commands: $ sudo chmodfind 0600 /etc/audit/rules.d/audit -type f -name "*.rules" -exec chmod 0600 {} + $ sudo chmod 0600 /etc/audit/rulesaudit.d/[customrulesfile].rules $ sudo chmod 0600 /etc/audit/auditd.conf

V-271587 in V1R7

Check text

Verify that OL 9 for PKI-based authentication has valid certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Check that the system has a valid DODDoW root CA installed with the following command: $ sudo openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem Example output: Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha256WithRSAEncryption Issuer: C = US, O = U.S. Government, OU = DODDoW, OU = PKI, CN = DOD Root CA 3 Validity Not Before: Mar 20 18:46:41 2012 GMT Not After: Dec 30 18:46:41 2029 GMT Subject: C = US, O = U.S. Government, OU = DODDoW, OU = PKI, CN = DOD Root CA 3 Subject Public Key Info: Public Key Algorithm: rsaEncryption If the root CA file is not a DODDoW-issued certificate with a valid date and installed in the "/etc/sssd/pki/sssd_auth_ca_db.pem" location, this is a finding.

Fix text

Configure OL 9, for PKI-based authentication, to validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Obtain a valid copy of the DODDoW root CA file from the PKI CA certificate bundle from cyber.mil and copy the DOD_PKE_CA_chainDoW_PKE_CA_chain.pem into the following file: /etc/sssd/pki/sssd_auth_ca_db.pem

V-271604 in V1R7

Discussion

Without the use of multifactor authentication (MFA), the ease of access to privileged functions is greatly increased. MultifactorMFA authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. The DODDoW Commoncommon Accessaccess Cardcard (CAC) with DODDoW-approved PKI is an example of multifactor authentication. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000105-GPOS-00052

V-271607 in V1R7

Check text

Verify that OL 9 implements Online Certificate Status Protocol (OCSP) and is using the proper digest value on the system with the following command: $ sudo grep certificate_verification /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf | grep -v "^#" certificate_verification = ocsp_dgst=sha512 If the certificate_verification line is missing from the [sssd] section, or is missing "ocsp_dgst=sha512", ask the administrator to indicate what type of multifactor authentication (MFA) is being used and how the system implements certificate status checking. If there is no evidence of certificate status checking being used, this is a finding.

Discussion

Using an authentication device, such as a DODDoW Commoncommon Accessaccess Cardcard (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, credentials stored on the authentication device will not be affected. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DODDoW CAC. OL 9 includes multiple options for configuring certificate status checking, but for this requirement focuses on the System Security Services Daemon (SSSD). By default, SSSD performs Online Certificate Status Protocol (OCSP) checking and certificate verification using a sha256 digest function. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000377-GPOS-00162

V-271608 in V1R7

Discussion

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 DODDoW data may be compromised. OL 9 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DODDoW requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.

V-271624 in V1R7

Title

OL 9 user account passwords for new users or password changes must have a 6180-day maximum password lifetime restriction in /etc/login.defs.

Check text

Verify that OL 9 enforces a 60180-day maximum password lifetime for new user accounts by running the following command: $ grep -i pass_max_days /etc/login.defs PASS_MAX_DAYS 60180 If the "PASS_MAX_DAYS" parameter value is greater than "60180", or commented out, this is a finding.

Fix text

Configure OL 9 to enforce a 6180-day maximum password lifetime. Add or modify the following line in the "/etc/login.defs" file: PASS_MAX_DAYS 6180

V-271631 in V1R7

Title

OL 9 user account passwords must have a 6180-day maximum password lifetime restriction.

Check text

Verify that OL 9 user account passwords have a 60-day maximum password lifetime restriction with the following commands: $ sudo awk -F: '$5 > 60180 {print $1 "" "" $5}' /etc/shadow $ sudo awk -F: '$5 &lt= 0 {print $1 "" "" $5}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding.

Fix text

Configure OL 9 so that noncompliant accounts to enforce a 6180-day maximum password lifetime restriction. $ sudo passwd -x 6180 [user]

V-271632 in V1R7

Discussion

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 increase exponentially the time and/or resources required to compromise the password. OL 9 uses "pwquality" as a mechanism to enforce password complexity. Configurations are set in the "etc/security/pwquality.conf" file. The "minlen", sometimes noted as minimum length, acts as a "score" of complexity based on the credit components of the "pwquality" module. By setting the credit components to a negative value, not only will those components be required, but they will not count toward the total "score" of "minlen". This will enable "minlen" to require a 15-character minimum. The DODDoW minimum password requirement is 15 characters.

V-271633 in V1R7

Title

OL 9 must require a boot loader superuser password.OL 9 must require authentication upon booting into single-user and maintenance modes.

Check text

Verify that OL 9 requires a bootpassword loaderfor superuserthe passwordGRUB with2 thebootloader followingto command: $prevent sudounauthorized grepmodifications "superusers"to /etc/grub2.cfgboot parameters. password_pbkdf2 superusers-account ${GRUB2_PASSWORD} ToCheck verify the bootunified loaderconfiguration superuserfile accountwhere passwordthe hasGRUB been2 set, and the password encrypted,is run the following commandstored: $ sudo catgrep -iw "GRUB2_PASSWORD" /boot/grub2/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.10000.C4E08AC72FBFF7E837FD267BFAD7AEB3D42DDC[password_hash] 2C99F2A94DD5E2E75C2DC331B719FE55D9411745F82D1B6CFD9E927D61925F9BBDD1CFAA0080E0 916F7AB46E0D.1302284FCCC52CD73BA3671C6C12C26FF50BA873293B24EE2A96EE3B57963E6D7 0C83964B473EC8F93B07FE749AA6710269E904A9B08A6BBACB00A2D242AD828 If athe "GRUB2_PASSWORD" entry does not exist, is commented out, or if the hash does not setbegin with "grub.pbkdf2.sha512", this is a finding.

Discussion

To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DODDoW-approved PKIs, all DODDoW systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.

V-271635 in V1R7

Title

The OL 9 file system automounter function must be disabled unless required.

Check text

Verify that OL 9 file system automount function has been disabled and masked with the following command: $ systemctl is-enabled autofs masked If the returned value is not "masked", and"disabled", isor "not documented as operational requirement with the information system security officer (ISSO)-found", this is a finding.

Discussion

AnWithout authenticationidentifying processdevices, resistsunidentified replayor attacksunknown ifdevices itmay isbe impracticalintroduced, tothereby achievefacilitating amalicious successfulactivity. Peripherals authenticationinclude, bybut recordingare andnot replayinglimited ato, previoussuch authenticationdevices messageas flash drives, external storage, and printers. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163

V-271639 in V1R7

Title

OL 9 must be configured to enable the display of the Standard Mandatory DODDoW Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.

Fix text

Configure OL 9 to display the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the system via a graphical user logon. Create a database to contain the system-widesystemwide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/01-banner-message Add the following lines to the [org/gnome/login-screen] section of the "/etc/dconf/db/local.d/01-banner-message": [org/gnome/login-screen] banner-message-enable=true Run the following command to update the database: $ sudo dconf update

V-271688 in V1R7

Title

OL 9 must display the Standard Mandatory DODoW Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.

Check text

This requirement assumes the use of the OL 9 default graphical user interface—the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify that OL 9 displays the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the operating system via a graphical user logon. Check that the operating system displays the exact Standard Mandatory DODDoW Notice and Consent Banner text with the command: $ gsettings get org.gnome.login-screen banner-message-text banner-message-text= 'You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.1nBy using this IS (which includes any device attached to this IS), you consent to the following conditions:1n-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.1n-At any time, the USG may inspect and seize data stored on this IS.1n-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.1n-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.1n-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.' Note: The "1n " characters are for formatting only. They will not be displayed on the graphical interface. If the banner does not match the Standard Mandatory DODDoW Notice and Consent Banner exactly, this is a finding.

Fix text

Configure the operating system to display the Standard Mandatory DODDoW Notice and Consent Banner before granting access to the system. Add the following lines to the [org/gnome/login-screen] section of the "/etc/dconf/db/local.d/01-banner-message": banner-message-text='You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.1nBy using this IS (which includes any device attached to this IS), you consent to the following conditions:1n-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.1n-At any time, the USG may inspect and seize data stored on this IS.1n-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.1n-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.1n-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.' Note: The "1n " characters are for formatting only. They will not be displayed on the graphical interface. Run the following command to update the database: $ sudo dconf update

Discussion

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 DODDoW 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." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088

V-271689 in V1R7

Check text

Verify that OL 9 securely compares internal information system clocks at least every 24 hours with an NTP server with the following command: $ grep maxpoll /etc/chrony.conf server 0.us.pool.ntp.mil iburst maxpoll 16 If the "maxpoll" option is set to a number greater than 16 or the line is commented out, this is a finding. Verify the "chrony.conf" file is configured to an authoritative DODDoW time source by running the following command: $ grep -i server /etc/chrony.conf server 0.us.pool.ntp.mil If the parameter "server" is not set or is not set to an authoritative DODDoW time source, this is a finding.

Discussion

Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Depending on the infrastructure being used the "pool" directive may not be supported. Authoritative time sources include the United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DODDoW network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146

V-271699 in V1R7

Discussion

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. 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. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DODDoW has defined the list of events for which OL 9 will provide an audit record generation capability as the following: 1. Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2. Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3. All account creations, modifications, disabling, and terminations; and 4. All kernel module load, unload, and restart actions.

V-271700 in V1R7

Discussion

Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. A DODDoW CAC with DODDoW-approved PKI is an example of multifactor authentication. Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055

V-271721 in V1R7

Check text

Verify that OL 9 requires reauthentication when using the "sudo" command to elevate privileges with the following command: $ sudo grep -i 'timestamp_timeout' /etc/sudoers /etc/sudoers.d/* /etc/sudoers:Defaults timestamp_timeout=0 If results are returned from more than one file location, this is a finding. If "timestamp_timeout" is set to a value other than "0" (including negative numbernumbers), is commented out, or nois resultsmissing are returnedentirely, this is a finding.

Fix text

Configure OLthe 9OS to reauthenticate "sudo"every commandsinvocation afterof the specified"sudo" timeout:command. Add the following line to "/etc/sudoers" or a file in "/etc/sudoers.d": Defaults timestamp_timeout=0 Remove any duplicate definitions.

V-271722 in V1R7

Discussion

Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DODDoW or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069

V-271745 in V1R7

Discussion

Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DODDoW or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Setting the kernel.perf_event_paranoid kernel parameter to "2" prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069

V-271746 in V1R7

Check text

Verify OL 9 is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command: $ sudo grep -iRiHs "^1s*CtrlAltDelBurstAction" /etc/systemd/system.conf /etc/systemd/system.conf.d/*.conf /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction.conf:CtrlAltDelBurstAction=none If the "CtrlAltDelBurstAction" is not set to "none", commented out, or is missing, this is a finding.

Fix text

Configure OL 9 to disable the CtrlAltDelBurstAction by adding it to a dropconfig file in athe "/etc/systemd/system.conf.d/" configurationdrop-in filedirectory: If no drop-in filedirectory exists, create one with the following command: $ sudo mkdir -p /etc/systemd/system.conf.d && sudotouch vi /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction.conf EditAdd the filesetting to contain the setting by adding the following textfile: $ echo "CtrlAltDelBurstAction=none Reload" the>> daemon for this change to take effect/etc/systemd/system. $ sudo systemctl daemonconf.d/55-reloadCtrlAltDel-BurstAction.conf

V-271751 in V1R7

Title

OL 9 must implement DODoW-approved encryption in the bind package.

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. 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. OL 9 incorporates system-widesystemwide crypto policies by default. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/ directory. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000426-GPOS-00190

V-271759 in V1R7

Discussion

Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DODDoW or other government agencies.

V-271779 in V1R7

Check text

Verify that OL 9 configures system accounts todo not have an interactive login shell. Run with the following command to list any system account (UID &lt 1000) that has an interactive shell, excluding authorized system utility accounts (root, sync, shutdown, halt): $ $ awk -F: '(($3 > 0 &lt1000& $3 &lt 1000) && $1 !~ /^(halt|sync|shutdown)$/ && $7 !~ /(nologin|false)$/) {print $1 ":" $3 ":" $7}' /etc/passwd root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin IdentifyIf the systemcommand accountsreturns from this listing that do not have a nologin shell. If any system account (other than the root account) has a login shell and it is not documented with the information system security officer (ISSO)output, this is a finding.

Fix text

Configure OL 9 so that all noninteractive accounts on the system do not have an interactive shell assigned to them. If the system account needs a shell assigned for mission operations, document the need with the information system security officer (ISSO). Run the following command to disable the interactive shell for a specific noninteractive user account: Replace &ltuser> with the user that has a login shell. $ sudo usermod --shell /usr/sbin/nologin &ltuser> Do not perform the steps in this section on the root account. Doing so will cause the system to become inaccessible.

V-271845 in V1R7

Check text

Verify that OL 9 rsyslog is configured to log cron events with the following command: Note: If another logging package is used, substitute the utility configuration file for "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files. $ grep -s "cron.1*" /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.info;mail.none;authpriv.none;d/99-cron-stig.none /var/log/messages /etc/rsyslog.conf:cron.* action(type="omfile" file="/var/log/cron ") If the command does not return a responseline demonstrating logging to /var/log/cron, checkperform fora functional cron test. Inject a message into the cron logging allfacility facilitieswith the following command: $ logger -p cron.info "STIG-TEST-CRON-LOGGING" Check if it successfully wrote to the dedicated log file with the following command: $ sudo grep "STIG-sTEST-CRON-LOGGING" /var/log/messagescron Jul /etc/rsyslog.conf16 /etc/rsyslog.d/*.conf /etc/rsyslog.conf11:*.info;mail.none;authpriv.none;cron.none /var/log/messages33:00 RHEL10Sim pdosadmin[33692]: STIG-TEST-CRON-LOGGING If "rsyslog" is not logging messages for the cron facility or all facilities, this is a finding.

Fix text

Configure "rsyslog" to log all cron messages by adding or updating the following line to "/etc/rsyslog.conf" or a configuration file in the /etc/rsyslog.d/ directory: cron.* /var/log/cron The rsyslog daemon must be restarted for the changes to take effect: $ sudo systemctl restart rsyslog.service

V-271853 in V1R7

Discussion

This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with OL 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DODDoW requirements for wireless data transmission and be approved for use by the authorizing official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the OL 9 operating system. Satisfies: SRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118, SRG-OS-000424-GPOS-00188, SRG-OS-000481-GPOS-00481

V-271859 in V1R7

Title

OL 9 must only allow the use of DODoW PKI-established certificate authorities (CAs) for authentication in the establishment of protected sessions to OL 9.

Check text

Verify OL 9 only allows the use of DODDoW PKI-established certificate authorities using the following command: $ trust list pkcs11:id=%7C%42%96%AE%DE%4B%48%3B%FA%92%F8%9E%8C%CF%6D%8B%A9%72%37%95;type=cert type: certificate label: ISRG Root X2 trust: anchor category: authority If any nonapproved CAs are returned, this is a finding.

Fix text

Configure OL 9 to only allow the use of DODDoW PKI-established certificate authorities. For each untrusted CA, export the certificate to a file and add it to the blocklist: $ trust dump --filter "pkcs11:id=%7C%42%96%AE%DE%4B%48%3B%FA%92%F8%9E%8C%CF%6D%8B%A9%72%37%95;type=cert" > /etc/pki/ca-trust/source/blocklist/ISRGRootX2 $ update-ca-trust Verify that the certificate is in the blocklist: $ trust list --filter=blocklist p11-kit: overriding trust for anchor in blocklist: ISRGRootX2 pkcs11:id=%7C%42%96%AE%DE%4B%48%3B%FA%92%F8%9E%8C%CF%6D%8B%A9%72%37%95;type=cert type: certificate label: ISRG Root X2 trust: distrusted category: authority pkcs11:id=%88%68%BF%E0%8E%35%C4%3B%38%6B%62%F7%28%3B%84%81%C8%0C%D7%4D;type=cert type: certificate label: Explicitly Distrust DigiNotar Root CA trust: distrusted category: authority

Discussion

Untrusted certificateCAs authorities (CA) can issue certificates, but they may be issued by organizations or individuals that seek to compromise DODDoW systems or by organizations with insufficient security controls. If the CA used for verifying the certificate is not aDoW DOD-approved CA, trust of this CA has not been established. The DODDoW will only accept PKI-certificates obtained from a DODDoW-approved internal or external certificate authority. Reliance on CAs for the establishment of secure sessions includes, for example, the use of SSL/TLS certificates.

V-271901 in V1R7

Check text

Note: For cloud hosted systems where "ClientAliveInterval" (V-271710) is configured, this setting is not applicable. Verify that OL 9 logs out sessions that are idle for 10 minutes with the following command: $ sudo grep -i ^StopIdleSessionSec /etc/systemd/logind.conf StopIdleSessionSec=600 If "StopIdleSessionSec" is not configured to "600" seconds, this is a finding.

V-279935 in V1R7