FreeBSD Security Advisories
2015-Aug-05 22:26 UTC
[FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-15:18.bsdpatch
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================FreeBSD-SA-15:18.bsdpatch Security Advisory The FreeBSD Project Topic: shell injection vulnerability in patch(1) Category: contrib Module: patch Announced: 2015-08-05 Credits: Martin Natano Affects: FreeBSD 10.x. Corrected: 2015-08-05 22:05:02 UTC (stable/10, 10.2-PRERELEASE) 2015-08-05 22:05:02 UTC (stable/10, 10.2-BETA2-p3) 2015-08-05 22:05:12 UTC (releng/10.2, 10.2-RC1-p2) 2015-08-05 22:05:12 UTC (releng/10.2, 10.2-RC2-p1) 2015-08-05 22:05:18 UTC (releng/10.1, 10.1-RELEASE-p17) CVE Name: CVE-2015-1418 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:https://security.FreeBSD.org/>. I. Background The patch(1) utility takes a patch file produced by the diff(1) program and apply the differences to an original file, producing a patched version. The patch(1) utility supports patches that uses ed(1) script format, as required by the POSIX.1-2008 standard. ed(1) is a line-oriented text editor. II. Problem Description Due to insufficient sanitization of the input patch stream, it is possible for a patch file to cause patch(1) to pass certain ed(1) scripts to the ed(1) editor, which would run commands. III. Impact This issue could be exploited to execute arbitrary commands as the user invoking patch(1) against a specically crafted patch file, which could be leveraged to obtain elevated privileges. IV. Workaround No workaround is available, but systems where a privileged user does not make use of patches without proper validation are not affected. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. A reboot is not required after updating. 2) To update your vulnerable system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install A reboot is not required after updating. 3) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. # fetch https://security.FreeBSD.org/patches/SA-15:18/bsdpatch.patch # fetch https://security.FreeBSD.org/patches/SA-15:18/bsdpatch.patch.asc # gpg --verify bsdpatch.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/10/ r286348 releng/10.1/ r286351 releng/10.2/ r286350 - ------------------------------------------------------------------------- To see which files were modified by a particular revision, run the following command, replacing NNNNNN with the revision number, on a machine with Subversion installed: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1418> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-15:18.bsdpatch.asc> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.6 (FreeBSD) iQIcBAEBCgAGBQJVwoplAAoJEO1n7NZdz2rn8D4QAM0077U1nLiJFIU1VcM9IOKp GeZ/w9SnkrKqKzAQpq3QS1hmw0TxvP8kuJNuRVFF6M15Woprfxccb8mDxM0ntru4 t8rq/QLO2jMWopf67Spv6jr6GLLQXkiyRwLEyr7L8a7MbrFwjO1wYt+8GnQ6Nsvn kNfCnbNKPr1gNYM1XsLS7Ej1kl7aBx3xGQXU4d9HlOs/1X7rnPCnGKuc3ZD2Z/N4 zu8pV4NMFhWyJsax+FVYEFxwyd2uEb73A35nz/sQhGiwGOCtL424KG+hwj9mnm45 8f4m+53b6RDcBh6xU41fghMsac2PVCzY2r9GXXXJNlfEa+KnSN8yC+CvtXYEM9BX 9Y5g6i++RVLLT7mwFdG86FjZxSGpDBXlkpZ4I9qiS4YC8MFO4qC7SFzufxtfOcg+ R+QSj+DWOfeHDcXjEkHGlqTW9poE2EDWXDLwlEoOykh9NLyWl6enYd8ZEI3GUqyJ FgKiICrs1vUuGhOhTCgjyQjQUc6jaV/GzhLBJfyxz5xYDpr7DIILxJ8uki2FJcHS tZhlNu6JNqpBlsWNspqjw7NSP2j58Uj0bBdwWvFNX8otQiIXVfkdY8RCjxstq5lT 3bcF6akAFEBx/f/VYM1lswLM/XdbORYC3asLu84BP541EDqdx9d88TeTKNPvyb4Q sGJ763WSlsoLrQDr8CUt =iR0L -----END PGP SIGNATURE-----