From owner-freebsd-security-notifications@FreeBSD.ORG Mon Mar 23 00:09:13 2009 Return-Path: Delivered-To: freebsd-security-notifications@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 27CF41065672; Mon, 23 Mar 2009 00:09:13 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 124EE8FC1A; Mon, 23 Mar 2009 00:09:13 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (cperciva@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id n2N09CrO065242; Mon, 23 Mar 2009 00:09:12 GMT (envelope-from security-advisories@freebsd.org) Received: (from cperciva@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id n2N09CEt065240; Mon, 23 Mar 2009 00:09:12 GMT (envelope-from security-advisories@freebsd.org) Date: Mon, 23 Mar 2009 00:09:12 GMT Message-Id: <200903230009.n2N09CEt065240@freefall.freebsd.org> X-Authentication-Warning: freefall.freebsd.org: cperciva set sender to security-advisories@freebsd.org using -f From: FreeBSD Security Advisories To: FreeBSD Security Advisories Precedence: bulk Cc: Subject: FreeBSD Security Advisory FreeBSD-SA-09:06.ktimer X-BeenThere: freebsd-security-notifications@freebsd.org X-Mailman-Version: 2.1.5 Reply-To: freebsd-security@freebsd.org List-Id: "Moderated Security Notifications \[moderated, low volume\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Mar 2009 00:09:14 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-09:06.ktimer Security Advisory The FreeBSD Project Topic: Local privilege escalation Category: core Module: kern Announced: 2009-03-23 Affects: FreeBSD 7.x Corrected: 2009-03-23 00:00:50 UTC (RELENG_7, 7.2-PRERELEASE) 2009-03-23 00:00:50 UTC (RELENG_7_1, 7.1-RELEASE-p4) 2009-03-23 00:00:50 UTC (RELENG_7_0, 7.0-RELEASE-p11) CVE Name: CVE-2009-1041 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background In FreeBSD 7.0, support was introduced for per-process timers as defined in the POSIX realtime extensions. This allows a process to have a limited number of timers running at once, with various actions taken when each timer reaches zero. II. Problem Description An integer which specifies which timer a process wishes to operate upon is not properly bounds-checked. III. Impact An unprivileged process can overwrite an arbitrary location in kernel memory. This could be used to change the user ID of the process (in order to "become root"), to escape from a jail, or to bypass security mechanisms in other ways. IV. Workaround No workaround is available, but systems without untrusted local users are not vulnerable. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to 7-STABLE, or to the RELENG_7_1 or RELENG_7_0 security branch dated after the correction date. 2) To patch your present system: The following patch has been verified to apply to FreeBSD 7.0 and 7.1 systems. 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-09:06/ktimer.patch # fetch http://security.FreeBSD.org/patches/SA-09:06/ktimer.patch.asc b) Apply the patch. # cd /usr/src # patch < /path/to/patch c) Recompile your kernel as described in and reboot the system. VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. CVS: Branch Revision Path - ------------------------------------------------------------------------- RELENG_7 src/sys/kern/kern_time.c 1.142.2.3 RELENG_7_1 src/UPDATING 1.507.2.13.2.7 src/sys/conf/newvers.sh 1.72.2.9.2.8 src/sys/kern/kern_time.c 1.142.2.2.2.2 RELENG_7_0 src/UPDATING 1.507.2.3.2.15 src/sys/conf/newvers.sh 1.72.2.5.2.15 src/sys/kern/kern_time.c 1.142.4.1 - ------------------------------------------------------------------------- Subversion: Branch/path Revision - ------------------------------------------------------------------------- stable/7/ r190301 releng/7.1/ r190301 releng/7.0/ r190301 - ------------------------------------------------------------------------- VII. References http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-1041 The latest revision of this advisory is available at http://security.FreeBSD.org/advisories/FreeBSD-SA-06:09.ktimer.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAknG0hQACgkQFdaIBMps37JA4gCfaznvIWKB/AU0cv6ojZUhheD4 MuYAnAp3wuz3E7gIX6VK7PeUVnPp/41o =MPIX -----END PGP SIGNATURE-----