All accounts must be assigned unique User Identification Numbers (UIDs).

From AIX 6.1 SECURITY TECHNICAL IMPLEMENTATION GUIDE

Associated with IA controls: IAIA-2, IAIA-1

Associated with: CCI-000764

SV-27067r1_rule All accounts must be assigned unique User Identification Numbers (UIDs).

Vulnerability discussion

Accounts that share a UID have full access to each others' files. This has the same effect as sharing a login. There is no way to assure identification, authentication, and accountability because the system sees them as the same user. If the duplicate UID is 0, this gives potential intruders another privileged account to attack.

Check content

Perform the following to ensure there are no duplicate UIDs: # usrck -n ALL If any duplicate UIDs are found, this is a finding.

Fix text

Edit user accounts to provide unique UIDs for each account.

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