documentation_complete: true


title: 'Ensure All Accounts on the System Have Unique User IDs'

description: 'Change user IDs (UIDs), or delete accounts, so each has a unique name.'

rationale: 'To assure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system.'

severity: medium

identifiers:
    cce@rhel8: CCE-89903-9
    cce@rhel9: CCE-88493-2
    cce@rhel10: CCE-89811-4
    cce@sle12: CCE-83196-6
    cce@sle15: CCE-83277-4
    cce@slmicro5: CCE-93780-5
    cce@slmicro6: CCE-94673-1

references:
    cis@sle12: 6.2.14
    cis@sle15: 6.2.14
    nist@sle12: IA-2,IA-2.1,IA-8,IA-8.1
    pcidss: Req-8.1.1
    srg: SRG-OS-000104-GPOS-00051,SRG-OS-000121-GPOS-00062
    stigid@ol8: OL08-00-020240
    stigid@sle12: SLES-12-010640
    stigid@sle15: SLES-15-010230

# The rule check uses password probe, which doesn't support offline mode
platform: system_with_kernel

ocil_clause: 'output is produced and the accounts listed are interactive user accounts'

ocil: |-
    Verify that {{{ full_name }}} contains no duplicate User IDs (UIDs) for interactive users.

    Check that the operating system contains no duplicate UIDs for interactive users with the following command:

    <pre>$ sudo awk -F ":" 'list[$3]++{print $1, $3}' /etc/passwd</pre>

warnings:
    - general: |-
        Automatic remediation of this control is not available due to unique requirements of each
        system.

fixtext: |-
    Edit the file "/etc/passwd" and provide each interactive user account that has a duplicate User ID (UID) with a unique UID.

srg_requirement: |-
        {{{ full_name }}} duplicate User IDs (UIDs) must not exist for interactive users.

vuldiscussion: |-
    To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system.
    Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following:
    1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and
    2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity.
