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.