The AIX SSH daemon must not allow compression.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-215296 | AIX7-00-002113 | SV-215296r991589_rule | CCI-000366 | medium |
| Description | ||||
| If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges. | ||||
| STIG | Date | |||
| IBM AIX 7.x Security Technical Implementation Guide | 2024-08-16 | |||
Details
Check Text (C-215296r991589_chk)
Note: If the installed version of OpenSSH is 7.4 or above, this requirement is not applicable.
Check the SSH daemon configuration for the Compression setting by running:
# grep -i Compression /etc/ssh/sshd_config | grep -v '^#'
Compression no
If the setting is not present, or it is not set to "no", this is a finding.
Fix Text (F-16492r294340_fix)
Edit the "/etc/ssh/sshd_config" file and add (or modify) the following line:
Compression no
Restart the SSH daemon:
# stopsrc -s sshd
# startsrc -s sshd