Amazon Linux 2023 must ensure all interactive users have unique User IDs (UIDs).

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

Satisfies: SRG-OS-000104-GPOS-00051, SRG-OS-000121-GPOS-00062, SRG-OS-000042-GPOS-00020

Verify Amazon Linux 2023 contains no duplicate UIDs for interactive users with the following command:

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

If output is produced and the accounts listed are interactive user accounts, this is a finding.

Configure Amazon Linux 2023 to contain no duplicate UIDs for interactive users.

Edit the file "/etc/passwd" and provide each interactive user account that has a duplicate UID with a unique UID.