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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2013.1144.2 Kernel memory disclosure in sctp(4) 11 September 2013 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: sctp Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Access Privileged Data -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2013-5209 Original Bulletin: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-13:10.sctp.asc Revision History: September 11 2013: Binary patch released for 9.2-RC1 August 22 2013: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-13:10.sctp Security Advisory The FreeBSD Project Topic: Kernel memory disclosure in sctp(4) Category: core Module: sctp Announced: 2013-08-22 Credits: Julian Seward, Michael Tuexen Affects: All supported versions of FreeBSD. Corrected: 2013-08-15 04:25:16 UTC (stable/9, 9.2-PRERELEASE) 2013-08-15 05:14:20 UTC (releng/9.2, 9.2-RC1-p1) 2013-08-15 05:14:20 UTC (releng/9.2, 9.2-RC2) 2013-08-22 00:51:48 UTC (releng/9.1, 9.1-RELEASE-p6) 2013-08-15 04:35:25 UTC (stable/8, 8.4-STABLE) 2013-08-22 00:51:56 UTC (releng/8.4, 8.4-RELEASE-p3) 2013-08-22 00:51:56 UTC (releng/8.3, 8.3-RELEASE-p10) CVE Name: CVE-2013-5209 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://security.FreeBSD.org/>. 0. Revision History v1.0 2013-08-22 Initial release. v1.1 2013-09-07 Binary patch released for 9.2-RC1. I. Background The SCTP protocol provides reliable, flow-controlled, two-way transmission of data. It is a message oriented protocol and can support the SOCK_STREAM and SOCK_SEQPACKET abstractions. The SCTP protocol checks the integrity of messages by validating the state cookie information that is returned from the peer. II. Problem Description When initializing the SCTP state cookie being sent in INIT-ACK chunks, a buffer allocated from the kernel stack is not completely initialized. III. Impact Fragments of kernel memory may be included in SCTP packets and transmitted over the network. For each SCTP session, there are two separate instances in which a 4-byte fragment may be transmitted. This memory might contain sensitive information, such as portions of the file cache or terminal buffers. This information might be directly useful, or it might be leveraged to obtain elevated privileges in some way. For example, a terminal buffer might include a user-entered password. IV. Workaround No workaround is available, but systems not using the SCTP protocol are not vulnerable. 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. 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 http://security.FreeBSD.org/patches/SA-13:10/sctp.patch # fetch http://security.FreeBSD.org/patches/SA-13:10/sctp.patch.asc # gpg --verify sctp.patch.asc b) Apply the patch. # cd /usr/src # patch < /path/to/patch c) Recompile your kernel as described in <URL:http://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the system. 3) 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 VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - - ------------------------------------------------------------------------- stable/8/ r254354 releng/8.3/ r254632 releng/8.4/ r254632 stable/9/ r254352 releng/9.1/ r254631 releng/9.2/ r254355 - - ------------------------------------------------------------------------- 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:http://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <other info on vulnerability> <URL:http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5209> The latest revision of this advisory is available at <URL:http://security.FreeBSD.org/advisories/FreeBSD-SA-13:10.sctp.asc> - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (FreeBSD) iEYEARECAAYFAlIu+g8ACgkQFdaIBMps37JBjgCgkRdb24STra3EjItZymFqU0S8 6rQAn0EQeP1D8BUCIbzR5uNYrrNv9Eo6 =2Ot5 - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. 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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 iQIVAwUBUi/TTxLndAQH1ShLAQKuCA//Rabw1IHq8+o13+i8ErhVI+Ylkfp3aylv u7vv0gOhdew1WrC6yRZNJzcOtwxbmFA0pX0whEmR8bDEVwjFpQ9hkUY/RVK+br/k 5aWxOa8Ab+/aZrPX1g1x5A6Jxr7Z0XdA5eAPhTuBhtl/MovOg1COjnXQSesg/P7M nExX2gs6cs8jLLfQt/M+PDU3UElDD+JstyAd1y5nZck8RP92FQf7BpsnuTUcTToF +Sg00hTuA42Ys9zkVHwwCyb0KHTzAERO47onWcZtuSd2tUsAyoSUdnZXSHFV2opg IfXW3/SCaYgDTdrFDYt0Ygolwx2KG84shi3nG+FM/Ul3JVZIe7kGFMCgrGE3SqfR TFYe723VJvfcCJTplG1j7eRuauxJuS71ObqMQXq05Wl3PJW11xpGWIwDW44q5XJs BwSUkOPOI1zWNVuQkOvnzWpVMcpTeC+WLQ2LS2knY3BG3chiygNjXkHKsfINlMLy ubbBeyWB8zbV+vE12WLKQFO+URTc/3TtBOONlm+pQTWOI4goJuxJctDwgbEB1LOu MLhlReOlJ6ZP/QPEfvHuhV4twKjem/DUIv8GOGVANPS+D5tK/5A8cGIsn1Z49dVE CbSCYh5Cc+9pjJAlo/JLRubsYmDuVOmPAQtneEdMlUzSXD5GchjcJYm1IWWsvhzS rYcIj3zXOQU= =g/jd -----END PGP SIGNATURE-----