cyberstrikeus CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.2.16
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection.
Rationale
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.
Audit Procedure
Command Line
Run the following command and verify the output:
sshd -T | grep -i maxsessions
Expected Result
maxsessions 10
Value should be 10 or less.
Remediation
Command Line
Edit the /etc/ssh/sshd_config file to set the parameter as follows:
MaxSessions 10
Default Value
MaxSessions 10
References
- NIST SP 800-53 Rev. 5: CM-6
CIS Controls
None
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Assessment Status
Automated