SLEM 5 SSH server must be configured to use only FIPS 140-2/140-3 validated key exchange algorithms.
An XCCDF Rule
Description
<VulnDiscussion>Without cryptographic integrity protections provided by FIPS 140-2/140-3 validated cryptographic algorithms, information can be viewed and altered by unauthorized users without detection. The system will attempt to use the first algorithm presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest algorithm available to secure the SSH connection.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-261336r996472_rule
- Severity
- High
- References
- Updated
Remediation - Manual Procedure
Configure the SSH server to use only FIPS 140-2/140-3 validated key exchange algorithms.
Add or modify the following line in the "/etc/ssh/sshd_config" file:
KexAlgorithms ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256