Title

The RHEL 8 SSH daemon must be configured to use system-wide crypto policies. (Cat II impact)

Discussion

Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-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. RHEL 8 incorporates system-wide 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/ directory. Satisfies: SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000125-GPOS-00065

Check Content

Verify that system-wide crypto policies are in effect: $ sudo grep CRYPTO_POLICY /etc/sysconfig/sshd # CRYPTO_POLICY= If the "CRYPTO_POLICY " is uncommented, this is a finding.

Fix Text

Configure the RHEL 8 SSH daemon to use system-wide crypto policies by adding the following line to /etc/sysconfig/sshd: # CRYPTO_POLICY= A reboot is required for the changes to take effect.

Additional Identifiers

Rule ID: SV-244526r877394_rule

Vulnerability ID: V-244526

Group Title: SRG-OS-000250-GPOS-00093

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.