FreeBSD Security Advisory FreeBSD-SA-16:29.bspatch
10 October, 2016 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:29.bspatch Security Advisory The FreeBSD Project Topic: Heap overflow vulnerability in bspatch Category: core Module: bsdiff Announced: 2016-10-10 Affects: All supported versions of FreeBSD. 2016-09-22 21:05:21 UTC (stable/11, 11.0-STABLE) 2016-09-27 19:36:12 UTC (releng/11.0, 11.0-RELEASE-p1) 2016-09-22 21:16:54 UTC (stable/10, 10.3-STABLE) 2016-10-10 07:18:54 UTC (releng/10.3, 10.3-RELEASE-p10) 2016-10-10 07:18:54 UTC (releng/10.2, 10.2-RELEASE-p23) 2016-10-10 07:18:54 UTC (releng/10.1, 10.1-RELEASE-p40) 2016-09-23 01:52:06 UTC (stable/9, 9.3-STABLE) 2016-10-10 07:19:16 UTC (releng/9.3, 9.3-RELEASE-p48) 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 bspatch utility generates newfile from oldfile and patchfile where patchfile is a binary patch built by bsdiff(1). II. Problem Description The implementation of bspatch is susceptible to integer overflows with carefully crafted input, potentially allowing an attacker who can control the patch file to write at arbitrary locations in the heap. This issue was partially addressed in FreeBSD-SA-16:25.bspatch, but some possible integer overflows remained. III. Impact An attacker who can control the patch file can cause a crash or run arbitrary code under the credentials of the user who runs bspatch, in many cases, root. IV. Workaround No workaround is available. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. No reboot is needed. Perform one of the following: 1) 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. Because this vulnerability exists in bspatch, a component used by freebsd-update, a special procedure must be followed to safely update. First, truncate bspatch to a zero byte file: # :> /usr/bin/bspatch FreeBSD-update will fall back to replacing bspatch, rather than applying a binary patch. Proceed with FreeBSD-update as usual: # freebsd-update fetch # freebsd-update install No reboot is needed. 2) 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-16:29/bspatch.patch # fetch https://security.FreeBSD.org/patches/SA-16:29/bspatch.patch.asc # gpg --verify bspatch.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/9/ r306222 releng/9.3/ r306942 stable/10/ r306215 releng/10.1/ r306941 releng/10.2/ r306941 releng/10.3/ r306941 stable/11/ r306213 releng/11.0/ r306379 - ------------------------------------------------------------------------- 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://gist.github.com/anonymous/e48209b03f1dd9625a992717e7b89c4f> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:29.bspatch.asc> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.13 (FreeBSD) iQIcBAEBCgAGBQJX+0OmAAoJEO1n7NZdz2rnMHQQALyzQ6rIFLMV+qfIKr/dxUmv frrY3rE8GbHNI6UYnlB7T97SZBVG2lOGpUO7sGNzsqAol+aBEn44mX88ijCQk+mc pIHcbwACkAG6u5c6nyelHAa3ZLc8PkPbNaryjfc9Y0vZxGFKI5ETpdN1nFxUBKRA eGt4h4GW3ZxHTkc3DDogDM6kBds3DYAnQjnqvkH6QesM/cMIdnU2NMjIrYDdtcsJ Mp92PqRl8/qCZxcpfoHSl3S190Dmu9KNjEwXdk8gvtr7aTe/OG9fcIOAwIJHMi/n E3tojTrSGLl0v9yuznG8rU0Hr6VyFNRv9i5QhPEQF4ZQ0HT2/naV0v/THMB1JdeR 8rszvO8HIdYkKEYPEp4RZ+QWJX36xK0ZOA0BSF3+OW6VYMIEB+iMvK1xAlGWmyJq D6f5AQuw559o4MNZ9gh1tXl+PXjYHvwSOrHb1EZ7mDZ3zVarn8TwUjxaE2ILIhjW wS+wqbxZt1eENfKbhLHxSavIE+Bi59ab/iymmOFtFdgDDDpQhzx13MUFM17v270g 1OCXnx7HLMIr5ibndJBQbjPmZT0InMM9856Hij8UhcFjyFpytCJie7sVcDFG9nNp z3VXrSIdEIA5MwaD6MYGW8nUfBwQnD/rSh6t2Tt4qz24FPk9K9pbzpb8CDIOImiF GnLZXJQlgmJ55XOa0EgR =uRNW -----END PGP SIGNATURE----- _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "firstname.lastname@example.org"