UIDs reserved for system accounts must not be assigned to non-system accounts.

From Oracle Linux 5 Security Technical Implementation Guide

Associated with: CCI-000366

SV-63277r1_rule UIDs reserved for system accounts must not be assigned to non-system accounts.

Vulnerability discussion

Reserved UIDs are typically used by system software packages. If non-system accounts have UIDs in this range, they may conflict with system software, possibly leading to the user having permissions to modify system files.

Check content

Check the UID assignments for all accounts. # cut -d: -f 1,3 /etc/passwd | egrep ":[1-4][0-9]{2}$|:[0-9]{1,2}$" Confirm all accounts with a UID of 499 and below are used by a system account. If a UID reserved for system accounts (0 - 499) is used by a non-system account, then this is a finding.

Fix text

Change the UID numbers for non-system accounts with reserved UIDs (those less or equal to 499).

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