Container-Optimized OS
TMA-COS-5.1.22
Ensure SSH MaxSessions is set to 4 or less
LowLevel 2Manual reviewcos
Description
The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection. To protect a system from denial of service due to a large number of concurrent sessions, use the rate limiting function of MaxSessions to protect availability of sshd logins and prevent overwhelming the daemon.
How it is checked
Audit method: Manual review
This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.
Run the following command and verify that output MaxSessions is 4 or less, or matches site policy: # sshd -T | grep -i maxsessions # maxsessions 4
How it is fixed
Fix method: Guidance or infrastructure patch
Edit the /etc/ssh/sshd_config file to set the parameter as follows: MaxSessions 4
Properties
- Operating systems
- Any
- Tags
- container-optimized-oscosssh
- Reference
- CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.22 Ensure SSH MaxSessions is set to 4 or less