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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.2585 OpenSSL Remote DoS vulnerability 3 November 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: openssl Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2016-8610 Original Bulletin: https://security.freebsd.org/advisories/FreeBSD-SA-16:35.openssl.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:35.openssl Security Advisory The FreeBSD Project Topic: OpenSSL Remote DoS vulnerability Category: contrib Module: openssl Announced: 2016-11-02 Affects: FreeBSD 9.x and FreeBSD 10.x. Corrected: 2016-11-02 07:09:31 UTC (stable/10, 10.3-STABLE) 2016-11-02 07:23:36 UTC (releng/10.3, 10.3-RELEASE-p12) 2016-11-02 07:24:14 UTC (releng/10.2, 10.2-RELEASE-p25) 2016-11-02 07:24:14 UTC (releng/10.1, 10.1-RELEASE-p42) 2016-11-02 07:09:31 UTC (stable/9, 9.3-STABLE) 2016-11-02 07:24:34 UTC (releng/9.3, 9.3-RELEASE-p50) CVE Name: CVE-2016-8610 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 FreeBSD includes software from the OpenSSL Project. The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library. The SSL alert protocol is a way to communicate problems within a SSL/TLS session. II. Problem Description Due to improper handling of alert packets, OpenSSL would consume an excessive amount of CPU time processing undefined alert messages. III. Impact A remote attacker who can initiate handshakes with an OpenSSL based server can cause the server to consume a lot of computation power with very little bandwidth usage, and may be able to use this technique in a leveraged Denial of Service attack. 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. Restart all daemons that use the library, or reboot the system. 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 Restart all daemons that use the library, or reboot the system. 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. [FreeBSD 10.x] # fetch https://security.FreeBSD.org/patches/SA-16:35/openssl-10.patch # fetch https://security.FreeBSD.org/patches/SA-16:35/openssl-10.patch.asc # gpg --verify openssl-10.patch.asc [FreeBSD 9.3] # fetch https://security.FreeBSD.org/patches/SA-16:35/openssl-9.patch # fetch https://security.FreeBSD.org/patches/SA-16:35/openssl-9.patch.asc # gpg --verify openssl-9.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>. Restart all daemons that use the library, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - - ------------------------------------------------------------------------- stable/9/ r308200 releng/9.3/ r308205 stable/10/ r308200 releng/10.1/ r308204 releng/10.2/ r308204 releng/10.3/ r308203 - - ------------------------------------------------------------------------- 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:http://seclists.org/oss-sec/2016/q4/224> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8610> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:35.openssl.asc> - -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.15 (FreeBSD) iQIcBAEBCgAGBQJYGZhkAAoJEO1n7NZdz2rnwbMQAOiGWegkYQodqBzNboK9U+6M 8Jt6HNrYDWAyzp+mZmWxgPWZMkGaNAsBEFXwZlHgs65RCbRczxr/kUWZx2/XHbM3 kGx5eNIq46BFIrTDPvUgNciorl/ncJGeO4SYEFBYImceDNwIQVtpfz1IUAve+LNW RYYICakWn8HPuqzmIFjQydMkoyEaHMwsmkv3nVNVX46sVIQ1umZ3RZsKtlPOQqNs sAa0HuOOQbeU2eJhhtcYcDEPNF7Do9WvSMnYrJQ/lE2SuatXq2tdbvZLV8ieiPoj 3AMf9p2yPpeqqO9yy19CayTSPmDiKMVQq8jikVomX5XkVqNKLrQoQfrvpwR0DWOW fwIDjZ1H9IXoqjVVZwp5GLfHhAURNjbsszF4B1lXQHI1D/p4bXyOOrcuM1JxHXRK UGvagbs30DWH+4Baph/UVOsFUhPU0sguPtpPa0XFxSIxB6qZJJGjdOh7el6aBYJu VxQuw1wWQvJPm9CsIIZrX4WYBcwS8ro82wsfNWO+ZC0j5UbMwh2joFgrbEdWNM3f MWVYuH5czzoJO85Nu7uGB+qa9GYqKkdwGRDnFshnvPhHHnpmGL/tLHM+Kqg7uDeu 8RsNaZ4PYChZh8YHVooOraDl0Nz0Ln/kok8GdsZUpNfuiXm3U9fLUCAFAdNUOlr6 PJuvkUEQRMlhG8tX3+11 =1gO7 - -----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 iQIVAwUBWBqMB4x+lLeg9Ub1AQikrxAAkZrz7j6hWKuCRyhHKFLEcHYVLxnCh16R /R3QK6H+YnVfGZ5mSsdCFIGz1vXh5wp2zlX49u9L9tRJR7BcWPuu4ZmLZRtH0/oe +VzRCr07W0Ljc83rpF3mC4wzgjJXviX8g5n9FthkyIy5FqnXYL/QCDv+gNgiR7DP vKs8GHIr/HI588QL9PTPAvwM02fml7wfsDJTNkmC7wWxI1XgM0FOhA32+WRWFRZ1 dJck7swahc13y2E7Gx3U2YQepLSWLIJvicNKBES0Kjmf+632IjZ6CMcMcIvushyC qqLTStWDrAenkziVlJjaTstFZeX9dnFydJW7UrE8uYn7LqSuopA1nkBgMj6Oumxi alpf0GKLn54zySobuOI1lZCzKfuEZQm2DEM91SOlwcxUV2Dix4hAw2y0wR1sVFZR 8PHOsbyYlzbDWn96sJ4UbXU4mJTYS68rT93jylOUCcsV4DkbtYuED3uRp++K45fe 0Klq+GdF0vuVVoa8dsSbq4BhEuvmv+++hGLVahiWlaNBy7Ml80QBeI5IzvBUbrQL JgmCWW4fiuXr0cr3l8pO/Z5uKAnSFG4sRrpZYuSrI6Uxh/EWO5WJ5fB54TQND0H1 FKnavCpGulwWcUPo+UA8ntH1R7yrl21tSP7x+hOlypJ2/aqrEL6rX3CUynMErQF0 RCtozHct1R8= =Fmbk -----END PGP SIGNATURE-----