TMA-COS-5.1.17

Ensure SSH LoginGraceTime is set to one minute or less

LowLevel 2Automatedcos

Description

The LoginGraceTime parameter specifies the time allowed for successful authentication to the SSH server. The longer the Grace period is the more open unauthenticated connections can exist. Like other session controls in this session the Grace Period should be limited to appropriate organizational limits to ensure the service is available for needed access. Setting the LoginGraceTime parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. It will also limit the number of concurrent unauthenticated connections While the recommended setting is 60 seconds (1 Minute), set the number based on site policy.

How it is checked

Audit method: Shell command

shell

alt0() { command -v grep >/dev/null 2>&1 || { echo "step1: grep not installed"; return 1; }; command -v sshd >/dev/null 2>&1 || { echo "step1: sshd not installed"; return 1; }; o=$(bash -c 'sshd -T | grep logingracetime' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'LoginGraceTime 60' || { echo step1: missing 'LoginGraceTime 60'; return 1; }; }; if alt0; then echo compliant; fi

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: LoginGraceTime 60

Properties

Operating systems: Any
Tags: container-optimized-oscosloggingssh
Reference: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.17 Ensure SSH LoginGraceTime is set to one minute or less

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target cos --level 2