GEN001170 - All files and directories must have a valid group owner.

Information

Files without a valid group owner may be unintentionally inherited if a group is assigned the same GID as the GID of the files without a valid group owner.

Solution

Change the group owner for each file without a valid group owner.
# chgrp <a-valid-group> /tmp/a-file-without-a-valid-group-owner

See Also

http://iasecontent.disa.mil/stigs/zip/U_STIG_Library_2015_07.zip