gzip before 1.3 in Solaris 8, when called with the -f or -force flags, will change the permissions of files that are hard linked to the target files, which allows local users to view or modify these files.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1654
https://exchange.xforce.ibmcloud.com/vulnerabilities/17577