Ubuntu 24.04 5.3.2.1 Ensure pam_unix module is enabled

components/pam.yml

@@ -61,6 +61,7 @@ rules:
 - accounts_password_pam_pwquality_system_auth
 - accounts_password_pam_retry
 - accounts_password_pam_ucredit
+- accounts_password_pam_unix_enabled
 - accounts_password_pam_unix_remember
 - accounts_password_pam_unix_rounds_password_auth
 - accounts_password_pam_unix_rounds_system_auth

controls/cis_ubuntu2404.yml

@@ -1850,8 +1850,9 @@ controls:
     levels:
       - l1_server
       - l1_workstation
-    status: planned
-    notes: TODO. Rule does not seem to be implemented, nor does it map to any rules in ubuntu2204 profile.
+    rules:
+      - accounts_password_pam_unix_enabled
+    status: automated
 
   - id: 5.3.2.2
     title: Ensure pam_faillock module is enabled (Automated)

linux_os/guide/system/accounts/accounts-pam/accounts_password_pam_unix_enabled/bash/shared.sh

@@ -0,0 +1,3 @@
+# platform = multi_platform_ubuntu
+
+{{{ bash_pam_unix_enable() }}}

linux_os/guide/system/accounts/accounts-pam/accounts_password_pam_unix_enabled/oval/shared.xml

@@ -0,0 +1,36 @@
+{{% set file_stem = ["auth","account","password","session"] %}}
+<def-group>
+  <definition class="compliance" id="{{{ rule_id }}}" version="1">
+  {{{ oval_metadata("Ensure pam_unix.so is properly configured in PAM configuration files") }}}
+    <criteria operator="AND" comment="Check if pam_unix.so is properly defined in all PAM files">      
+      {{% for stem in file_stem %}}
+      <criterion test_ref="test_pam_unix_common_{{{ stem }}}"
+          comment="pam_unix has correctly set in common-{{{ stem }}}"/>
+      {{% endfor %}}
+    </criteria>
+  </definition>
+
+  <!-- Check occurrences of pam_unix.so in common-{auth,account,password} file -->
+  {{% macro test_pam_unix(stem) %}}
+  <ind:textfilecontent54_test check="all" id="test_pam_unix_common_{{{ stem }}}" version="1"
+        check_existence="only_one_exists"
+        comment="No more than one pam_unix.so is expected in {{{ stem }}} section of /etc/pam.d/common-{{{ stem }}}">
+    <ind:object object_ref="obj_pam_unix_common_{{{ stem }}}" />
+  </ind:textfilecontent54_test>
+  {{% endmacro %}}
+
+  {{% macro object_pam_unix(stem) %}}
+  <ind:textfilecontent54_object id="obj_pam_unix_common_{{{ stem }}}" version="1"
+        comment="Get the occurrences of pam_unix.so in {{{ stem }}} section of /etc/pam.d/common-{{{ stem }}}">
+    <ind:filepath>/etc/pam.d/common-{{{ stem }}}</ind:filepath>
+    <ind:pattern operation="pattern match">^[\s]*{{{stem}}}[\s]+(required|\[(?=.*?\bsuccess=\d+\b)?(?=.*?\bnew_authtok_reqd=ok\b)?(?=.*?\bdefault=ignore\b)?.*\])[\s]+pam_unix\.so.*$</ind:pattern>
+    <ind:instance datatype="int" operation="equals">1</ind:instance>
+  </ind:textfilecontent54_object>
+  {{% endmacro %}}
+
+  {{% for file in file_stem %}}
+  {{{ test_pam_unix(stem=file) }}}
+  {{{ object_pam_unix(stem=file) }}}
+  {{% endfor %}}
+
+</def-group>

linux_os/guide/system/accounts/accounts-pam/accounts_password_pam_unix_enabled/rule.yml

@@ -0,0 +1,30 @@
+documentation_complete: true
+
+
+title: Verify pam_unix module is activated
+
+description: |-
+    <tt>pam_unix</tt> is the standard Unix authentication module. It uses standard calls from the
+    system's libraries to retrieve and set account information as well as authentication.
+    Usually this is obtained from the <tt>/etc/passwd</tt> and if shadow is enabled, the
+    <tt>/etc/shadow</tt> file as well.
+    <br /><br />
+    The account component performs the task of establishing the status of the user's
+    account and password based on the following shadow elements: <tt>expire,
+    last_change, max_change, min_change, warn_change</tt>. In the case of the latter, it may
+    offer advice to the user on changing their password or, through the
+    <tt>PAM_AUTHTOKEN_REQD</tt> return, delay giving service to the user until they have
+    established a new password. The entries listed above are documented in the shadow(5)
+    manual page. Should the user's record not contain one or more of these entries, the
+    corresponding shadow check is not performed.
+    <br /><br />
+    The authentication component performs the task of checking the users credentials
+    (password). The default action of this module is to not permit the user access to a
+    service if their official password is blank.
+
+rationale: |-
+    The system should only provide access after performing authentication of a user.
+
+severity: medium
+
+platform: package[pam]