OL07-00-040712 - The Oracle Linux operating system SSH server must be configured to use only FIPS-validated key exchange algorithms.

Information

The use of FIPS-validated cryptographic algorithms is enforced by enabling kernel FIPS mode. In the event that kernel FIPS mode is disabled, the use of nonvalidated cryptographic algorithms will be permitted systemwide. The SSH server configuration must manually define only FIPS-validated key exchange algorithms to prevent the use of nonvalidated algorithms.

Solution

Configure the SSH server to use only FIPS-validated key exchange algorithms by adding or modifying the following line in '/etc/ssh/sshd_config':

KexAlgorithms ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256

Restart the 'sshd' service for changes to take effect:

$ sudo systemctl restart sshd

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Oracle_Linux_7_V2R14_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-17(2), CAT|II, CCI|CCI-001453, Rule-ID|SV-255899r880582_rule, STIG-ID|OL07-00-040712, Vuln-ID|V-255899

Plugin: Unix

Control ID: ca9465acef49532f0de9a7488ce614b0ef5a5deaf48e164569852893c8a883c4