4.2.4 Ensure legacy NIS markers are removed

Information

If NIS has been de-installed in the environment, or has historically been used, ensure the + markers are removed from /etc/passwd and /etc/group

The + entries in /etc/passwd and /etc/group were used as markers to insert data from a NIS map. These entries may provide an avenue for attackers to gain privileged access on the system. The + entries must be deleted if they still exist.

Solution

Examine the /etc/passwd and /etc/group files:

grep "^+" /etc/passwd /etc/group

If the above command yields output, delete the + line:

vi /etc/passwd
vi /etc/group

See Also

https://workbench.cisecurity.org/benchmarks/10385

Item Details

Category: ACCESS CONTROL, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|AC-5, 800-53|AC-6, 800-53|MP-2, CSCv7|14.6

Plugin: Unix

Control ID: 876da5cf17c54915678acb87af8365f6f5e6bce9bd62eea836d740cac17c7819