The do_ed_script function in pch.c in GNU patch through 2.7.6 and patch in FreeBSD 10.1 before 10.1-RELEASE-p17 10.2 before 10.2-BETA2-p3 10.2-RC1 before 10.2-RC1-p2 and 0.2-RC2 before 10.2-RC2-p1 allows remote attackers to execute arbitrary commands via a crafted patch file because a '!' character can be passed to the ed program.