Title

The SSH daemon must not accept environment variables from the client or must only accept those pertaining to locale. (Cat III impact)

Discussion

Environment variables can be used to change the behavior of remote sessions and should be limited. Locale environment variables specify the language, character set, and other features modifying the operation of software to match the user's preferences.

Check Content

Check the SSH daemon configuration for the AcceptEnv setting. # grep -i AcceptEnv /etc/ssh/sshd_config | grep -v '^#' If any line is returned other than those permitting LOCALE or LC_* environment variables, this is a finding.

Fix Text

Edit the SSH daemon configuration and remove (or edit) the AcceptEnv setting(s) to only accept LOCALE or LC_* environment variables.

Additional Identifiers

Rule ID: SV-26771r1_rule

Vulnerability ID: V-22477

Group Title: GEN005528

Expert Comments

CCIs tied to check.

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