FreeBSD : gzip -- directory traversal and permission race vulnerabilities (63bd4bad-dffe-11d9-b875-0001020eed82)
Medium Nessus Plugin ID 18960
SynopsisThe remote FreeBSD host is missing a security-related update.
DescriptionProblem Description Two problems related to extraction of files exist in gzip :
The first problem is that gzip does not properly sanitize filenames containing '/' when uncompressing files using the -N command line option.
The second problem is that gzip does not set permissions on newly extracted files until after the file has been created and the file descriptor has been closed. Impact The first problem can allow an attacker to overwrite arbitrary local files when uncompressing a file using the -N command line option.
The second problem can allow a local attacker to change the permissions of arbitrary local files, on the same partition as the one the user is uncompressing a file on, by removing the file the user is uncompressing and replacing it with a hardlink before the uncompress operation is finished. Workaround Do not use the -N command line option on untrusted files and do not uncompress files in directories where untrusted users have write access.
SolutionUpdate the affected package.