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5.1.18 Ensure sshd MaxSessions is configured

Information

The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection.

More information about the openSSH server configuration is available in the "Configure SSH Server" section overview.

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.

Solution

Create or edit a *.conf file in the /etc/ssh/sshd_config.d/ directory to set the MaxSessions parameter to 10 or less above any Include and Match entries as follows:

MaxSessions 10

See Also

https://workbench.cisecurity.org/benchmarks/26236

Item Details

Category: CONFIGURATION MANAGEMENT, IDENTIFICATION AND AUTHENTICATION

References: 800-53|CM-1, 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|IA-5

Plugin: Unix

Control ID: 95a50cd8dddf3a8e7ee0e6d4216e601494fb8cf9acd35ee9760258d040694915