AIX must turn on SSH daemon reverse name checking.

If reverse name checking is off, SSH may allow a remote attacker to circumvent security policies and attempt to or actually login from IP addresses that are not permitted to access resources.

Check the SSH daemon configuration for the "VerifyReverseMapping" setting using command:

# grep -i VerifyReverseMapping /etc/ssh/sshd_config | grep -v '^#' VerifyReverseMapping yes

If the setting is not present or the setting is "no", this is a finding.

Edit the "/etc/sshd/sshd_config" file and add the following line: VerifyReverseMapping yes

Restart the SSH daemon: # stopsrc -s sshd # startsrc -s sshd