The SSH daemon must be configured to only use FIPS 140-2 approved ciphers.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22458	GEN005505	SV-37824r3_rule		Medium

Description
DoD information systems are required to use FIPS 140-2 approved ciphers. SSHv2 ciphers meeting this requirement are 3DES and AES.

STIG	Date
Red Hat Enterprise Linux 5 Security Technical Implementation Guide	2017-03-01

Details

Check Text ( C-37025r1_chk )
Check the SSH daemon configuration for allowed ciphers. # grep -i ciphers /etc/ssh/sshd_config | grep -v '^#' If no lines are returned, or the returned ciphers list contains any cipher not starting with "3des" or "aes", this is a finding

Fix Text (F-32293r4_fix)
Edit the SSH daemon configuration and remove any ciphers not starting with "3des" or "aes" and remove any ciphers ending with "cbc". If necessary, add a "Ciphers" line. Ciphers aes256-ctr,aes192-ctr,aes128-ctr Restart the SSH daemon. # /sbin/service sshd restart