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Servers – Remove Legacy '+' Entries from Shadow
Support > Fixing Checks > Server
06 March, 2026
This check ensures that there are no legacy '+' entries in the /etc/shadow file.
Historically, the + character was used as a placeholder for inserting user account information from
Network Information Service (NIS) maps.
Modern systems typically do not require these entries. If present, they may allow attackers to gain unauthorized or privileged access to the system through outdated authentication mechanisms.
Check Details
- Resource: Server
- Check: Check Legacy Shadow Plus
-
Risk: Legacy
'+'entries in the/etc/shadowfile may allow attackers to exploit outdated authentication mechanisms, potentially leading to unauthorized or privileged system access.
Remediation Steps
- Open a terminal session on the server with root or sudo privileges.
-
Check whether any legacy
'+'entries exist in the/etc/shadowfile.grep '^\+:' /etc/shadow
-
If the command returns any output, open the
/etc/shadowfile for editing.sudo nano /etc/shadow
-
Locate any lines beginning with the
'+'character and remove those entries carefully. - Save the file and exit the editor after removing the legacy entries.
-
Run the audit command again to confirm that no legacy
'+'entries remain in the file.grep '^\+:' /etc/shadow
- If the command returns no output, the system is correctly configured.