4.2.17 Ensure sshd MaxStartups is configured

Information

The MaxStartups parameter specifies the maximum number of concurrent unauthenticated connections to the SSH daemon.

To protect a system from denial of service due to a large number of pending authentication connection attempts, use the rate limiting function of MaxStartups to protect availability of sshd logins and prevent overwhelming the daemon.

Solution

Edit the /etc/ssh/sshd_config file to set the parameter above any Include entries as follows:

MaxStartups 10:30:60

Note: First occurrence of a option takes precedence. If Include locations are enabled, used, and order of precedence is understood in your environment, the entry may be created in a file in Include location.

See Also

https://workbench.cisecurity.org/benchmarks/15289

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION

References: 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|CM-7(1), 800-53|CM-9, 800-53|SA-3, 800-53|SA-8, 800-53|SA-10, CSCv7|5.1

Plugin: Unix

Control ID: d74fb307f4a60777c539e02b9ca91a253df5224231ae69c20cad4d2d7f684473