Lynis Security Controls

AUTH-9208 - Duplicate accounts or IDs


Lynis checks for any duplicates by checking the passwd file and count them. Any ID which shows up more than a single time is reported as a finding. Accounts and user IDs should be unique to enable proper accounting. Using several accounts with the same ID may result in data loss.



How to solve

Check for duplicate IDs (see shell script) and remove a duplicate, or give the second user a new ID.

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Linux and Unix System Hardening

This information is provided as part of the Lynis community project. It is related to Lynis control AUTH-9208. All information should be considered as-is, without guarantees. Any advice or snippets should be tested before implementing in production environments.


Lynis is a technical security audit tool for Unix flavors like Linux, macOS, AIX, Solaris, and *BSD. It is open source software and free to use. The project has an active community, including open development via GitHub.

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