FreeBSD -- shell injection vulnerability in patch(1)

Problem Description:
Due to insufficient sanitization of the input patch
stream, it is possible for a patch file to cause patch(1)
to run commands in addition to the desired SCCS or RCS
commands.
Impact:
This issue could be exploited to execute arbitrary
commands as the user invoking patch(1) against a specially
crafted patch file, which could be leveraged to obtain
elevated privileges.