-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:25.bspatch Security Advisory The FreeBSD Project Topic: Heap vulnerability in bspatch Category: core Module: bsdiff Announced: 2016-07-25 Affects: All supported versions of FreeBSD. Corrected: 2016-07-25 14:52:12 UTC (stable/11, 11.0-BETA2-p1) 2016-07-25 14:52:12 UTC (stable/11, 11.0-BETA1-p1) 2016-07-25 14:53:04 UTC (stable/10, 10.3-STABLE) 2016-07-25 15:04:17 UTC (releng/10.3, 10.3-RELEASE-p6) 2016-07-25 15:04:17 UTC (releng/10.2, 10.2-RELEASE-p20) 2016-07-25 15:04:17 UTC (releng/10.1, 10.1-RELEASE-p37) 2016-07-25 14:53:04 UTC (stable/9, 9.3-STABLE) 2016-07-25 15:04:17 UTC (releng/9.3, 9.3-RELEASE-p45) CVE Name: CVE-2014-9862 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . 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 does not check for a negative value on numbers of bytes read from the diff and extra streams, allowing an attacker who can control the patch file to write at arbitrary locations in the heap. This issue was first discovered by The Chromium Project and reported independently by Lu Tung-Pin to the FreeBSD project. 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 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. No reboot is needed. 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 No reboot is needed. 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-16:25/bspatch.patch # fetch https://security.FreeBSD.org/patches/SA-16:25/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 . VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/9/ r303301 releng/9.3/ r303304 stable/10/ r303301 releng/10.1/ r303304 releng/10.2/ r303304 releng/10.3/ r303304 stable/11/ r303300 - ------------------------------------------------------------------------- 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: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.13 (FreeBSD) iQIcBAEBCgAGBQJXlir7AAoJEO1n7NZdz2rnTtAP/iFnhrcmRuxmeMGtVPWHZFhH /I2iB62wGf4vNGVedwh3fHPEgjEpMvDVP7S+OCLB7Fnf+Mwm9uL47cjxdr/P5dy8 iKRsojG7HVE3Iia7DyaSEQwbJMQZGWsy2wr9epiHPoOpnSaWKUBx94C+oc7gPdM5 8LW5OpUgSpFCztQ82gbM/2Bjy5OREJQP6ASW62WO+MkD7n+ZUzsUCdR13bzvpA23 BaNeInQArn5Zf3OiZXjQ9Go1muml2llQmqxeb8p3V9IbJ3mdUBQat1AtF/yXfpWA tkUfgqAaoKbjOrk22h/wBRssPlqqftZDXWqi2KlkEltqyU1evnsb5UVCu0SZdgkW lQlnE1vymJCnxC211SweDNbbP8laR0OpjRxUxljSXVMXag4Lh9+9aD6zIZ9zZNi7 MxXEasLZViwq8gEbZLlLUfcOQVv6T+3jTiH8aRUYFp5PsBGBgQCAQgGCEaztQTNr lnSp/rqnP7FEu7gsHtP3wGK03RItNketbKMSUzV5eXiWmVYC3a6/WboqqJuqhDka zs3W0h0Fw6iqk6CfImHnhD1unarXnSQU5vRcf9srnUvS0XgYS/113BQK23SjGmki OIJe3Wm0CrcChAf8lKdeyPlKFcN906EkQ8Hh8vB00B9BZCXYLY9zBK6lW40NA1UN cy+ljfLX/xwCNIJJXdwH =FL3H -----END PGP SIGNATURE-----