{"description": "Add the <code>nosuid</code> option to the fourth column of <tt>/etc/fstab</tt> for the line which controls mounting of\nany NFS mounts.", "rationale": "NFS mounts should not present suid binaries to users. Only vendor-supplied suid executables\nshould be installed to their default location on the local filesystem.", "severity": "medium", "references": {"cis-csc": ["12", "13", "14", "15", "16", "18", "3", "5"], "cobit5": ["APO01.06", "DSS05.04", "DSS05.07", "DSS06.02"], "isa-62443-2009": ["4.3.3.7.3"], "isa-62443-2013": ["SR 2.1", "SR 5.2"], "iso27001-2013": ["A.10.1.1", "A.11.1.4", "A.11.1.5", "A.11.2.1", "A.13.1.1", "A.13.1.3", "A.13.2.1", "A.13.2.3", "A.13.2.4", "A.14.1.2", "A.14.1.3", "A.6.1.2", "A.7.1.1", "A.7.1.2", "A.7.3.1", "A.8.2.2", "A.8.2.3", "A.9.1.1", "A.9.1.2", "A.9.2.3", "A.9.4.1", "A.9.4.4", "A.9.4.5"], "nist": ["AC-6", "AC-6(1)", "CM6(a)"], "nist-csf": ["PR.AC-4", "PR.DS-5"], "srg": ["SRG-OS-000480-GPOS-00227"]}, "control_references": {}, "components": [], "identifiers": {}, "ocil_clause": "the setting does not show", "ocil": "To verify the <tt>nosuid</tt> option is configured for all NFS mounts, run\nthe following command:\n<pre>$ mount | grep nfs</pre>\nAll NFS mounts should show the <tt>nosuid</tt> setting in parentheses. This\nis not applicable if NFS is not implemented.", "oval_external_content": null, "fixtext": "Configure the \"/etc/fstab\" to use the \"nosuid\" option on file systems that are being imported via NFS.", "checktext": "", "vuldiscussion": "", "srg_requirement": "Ubuntu 22.04 must prevent files with the setuid and setgid bit set from being executed on file systems that are imported via Network File System (NFS).", "warnings": [], "conflicts": [], "requires": [], "policy_specific_content": {"stig": {"srg_requirement": "Ubuntu 22.04 must prevent files with the setuid and setgid bit set from being executed on file systems that are imported via Network File System (NFS).", "vuldiscussion": "The \"nosuid\" mount option causes the system not to execute \"setuid\" and \"setgid\" files with owner privileges. This option must be used for mounting any file system not containing approved \"setuid\" and \"setguid\" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.", "checktext": "Note: If no NFS mounts are configured, this requirement is Not Applicable.\n\nVerify Ubuntu 22.04 has the \"nosuid\" option configured for all NFS mounts with the following command:\n\n$ grep nfs /etc/fstab\n\n192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5:krb5i:krb5p\n\nIf the system is mounting file systems via NFS and the \"nosuid\" option is missing, this is a finding.", "fixtext": "Update each NFS mounted file system to use the \"nosuid\" option on file systems that are being imported via NFS."}}, "platform": "nfs_mount_defined", "platforms": ["nfs_mount_defined"], "sce_metadata": {}, "inherited_platforms": ["system_with_kernel"], "cpe_platform_names": ["nfs_mount_defined"], "inherited_cpe_platform_names": ["system_with_kernel"], "bash_conditional": null, "fixes": {}, "title": "Mount Remote Filesystems with nosuid", "definition_location": "/aptdata/openscap/scap-security-guide/linux_os/guide/services/nfs_and_rpc/nfs_configuring_clients/mounting_remote_filesystems/mount_option_nosuid_remote_filesystems/rule.yml", "template": {"name": "mount_option_remote_filesystems", "vars": {"mount_has_to_exist": "yes", "mountoption": "nosuid", "mountpoint": "remote_filesystems"}, "backends": {}}}