IBM AIX
TMA-AIX-4.6.3.12
Ensure sshd MaxAuthTries is configured
Description
The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. When the login failure count reaches half the number, error messages will be written to the syslog file detailing the login failure. Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. While the recommended setting is 4, set the number based on site policy. Audit: evaluates the effective configuration from `sshd -T` (Match blocks must be reviewed separately).
How it is checked
Audit method: Shell command
command -v sshd >/dev/null 2>&1 || exit 1; out=$(sshd -T 2>/dev/null) || exit 1; r=compliant; for p in '^maxauthtries[[:blank:]]+[1-4]$'; do printf '%s\n' "$out" | grep -Eiq -- "$p" || r="not matched: $p"; done; echo "$r"- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
Edit the/etc/ssh/sshd_config file to set the parameter as follows:: MaxAuthTries 4 Re-cycle the sshd daemon to pick up the configuration changes: stopsrc -s sshd startsrc -s sshd
Properties
- Operating systems
- Any
- Tags
- aixssh
- Reference
- CIS IBM AIX 7 Benchmark v1.2.0 - 4.6.3.12 Ensure sshd MaxAuthTries is configured
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target aix