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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.2370 Heap overflow vulnerability in bspatch 11 October 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: bspatch Publisher: FreeBSD Operating System: FreeBSD UNIX variants (UNIX, Linux, OSX) Impact/Access: Root Compromise -- Existing Account Denial of Service -- Existing Account Resolution: Patch/Upgrade Original Bulletin: https://security.freebsd.org/advisories/FreeBSD-SA-16:29.bspatch.asc Comment: This advisory references vulnerabilities in products which run on platforms other than FreeBSD. It is recommended that administrators running bspatch check for an updated version of the software for their operating system. - --------------------------BEGIN INCLUDED TEXT-------------------- - -----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----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBV/yBMox+lLeg9Ub1AQgXihAAk6Ko394nQlHP6vEbQfwhfWfaJgd8GFCM MKpWgvCLcswJTDdDmjzOv0UZh5aFK0A6eMOzxsdBwoPMaTr7oB4yF74SLkHZ1HxX Lg324uqDN9JzHhZoEmQzm1uPDrjI5R8ve53K3//AGGqwGEM26OvJCBx2pkbn9ltc AdXbTZME0JtfHC7bX8WaO+MoqWSivuvbNLDgPqZyXo4ZIxW/ezHGBQidDJH19MU7 ZzAo++/8jJk81tgvg6ZNVzTFaevicJgENT/I/Uf1EdVh6f0rPrCKgDbQ2B2SwcKf 2LmSi/GuY6pLvChhwKRd6cLFtmd47MPSUjxbYaQ7vnqpeW/VOClj3tHRU4sH8mTc RA7BBryYwKuVm3T02KPFruuNiki9ulfMOlb1o/S4IlgPLgbPH19opvTP1i9/plEu 6YeL6qAaiqqvs6XlRJeZfcrdooaP2DoJNk6kmge2p+DBab6mou106ohSJoZCTdiD vvB9uhDfGma+6aw8kK2jxxLmG18Ja9dsdtkHiU3N1GF3BqGOIsPvH0YirPMoF0JZ WpLSzyy2qyyzMc5cMaP/AJw1wKehHflV59XWYhRbuTAdeJQfpx0iX6C1GHmwktsy aWg0lGgYrztliwCUbvYI5YNlxWHXcdjS8tP6mQvVu8lFdtPtk0k0US2LFwAyKdvC w5edo217bUg= =aW0A -----END PGP SIGNATURE-----