{"description": "The <tt>MaxSessions</tt> parameter specifies the maximum number of open sessions permitted\nfrom a given connection. To set MaxSessions edit\n<tt>/etc/ssh/sshd_config</tt> as follows: <pre>MaxSessions <sub idref=\"var_sshd_max_sessions\" /></pre>", "rationale": "To protect a system from denial of service due to a large number of concurrent\nsessions, use the rate limiting function of MaxSessions to protect availability\nof sshd logins and prevent overwhelming the daemon.", "severity": "medium", "references": {"cis": ["5.1.17"], "pcidss4": ["2.2.6", "2.2"]}, "control_references": {"cis": ["5.1.17"], "pcidss4": ["2.2.6", "2.2"]}, "components": [], "identifiers": {}, "ocil_clause": "MaxSessions is not configured or not configured correctly", "ocil": "Run the following command to see what the max sessions number is:\n<pre>$ sudo grep MaxSessions /etc/ssh/sshd_config</pre>\nIf properly configured, the output should be:\n<pre>MaxSessions <sub idref=\"var_sshd_max_sessions\" /></pre>", "oval_external_content": null, "fixtext": "", "checktext": "", "vuldiscussion": "", "srg_requirement": "", "warnings": [], "conflicts": [], "requires": [], "policy_specific_content": {}, "platform": null, "platforms": [], "sce_metadata": {}, "inherited_platforms": ["system_with_kernel"], "cpe_platform_names": [], "inherited_cpe_platform_names": ["system_with_kernel"], "bash_conditional": null, "fixes": {}, "title": "Set SSH MaxSessions limit", "definition_location": "/aptdata/openscap/scap-security-guide/linux_os/guide/services/ssh/ssh_server/sshd_set_max_sessions/rule.yml", "template": {"name": "sshd_lineinfile", "vars": {"parameter": "MaxSessions", "xccdf_variable": "var_sshd_max_sessions", "datatype": "int", "backends": {"oval": "off"}}, "backends": {}}}