{"description": "The MaxStartups parameter specifies the maximum number of concurrent unauthenticated\nconnections to the SSH daemon. Additional connections will be dropped until authentication\nsucceeds or the LoginGraceTime expires for a connection. To configure MaxStartups, you should\nadd or edit the following line in the <tt>/etc/ssh/sshd_config</tt> file:\n<pre>MaxStartups <sub idref=\"var_sshd_set_maxstartups\" /></pre>", "rationale": "To protect a system from denial of service due to a large number of pending authentication\nconnection attempts, use the rate limiting function of MaxStartups to protect availability of\nsshd logins and prevent overwhelming the daemon.", "severity": "medium", "references": {"cis": ["5.1.18"], "pcidss4": ["2.2.6", "2.2"]}, "control_references": {"cis": ["5.1.18"], "pcidss4": ["2.2.6", "2.2"]}, "components": [], "identifiers": {}, "ocil_clause": "maxstartups is not configured", "ocil": "To check if MaxStartups is configured, run the following command:\n<pre>$ sudo grep -r ^[\\s]*MaxStartups /etc/ssh/sshd_config*</pre>\nIf configured, this command should output the configuration.", "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": "Ensure SSH MaxStartups is configured", "definition_location": "/aptdata/openscap/scap-security-guide/linux_os/guide/services/ssh/ssh_server/sshd_set_maxstartups/rule.yml", "template": {"name": "sshd_lineinfile", "vars": {"parameter": "MaxStartups", "xccdf_variable": "var_sshd_set_maxstartups", "datatype": "string", "backends": {"oval": "off"}}, "backends": {}}}