FreeBSD Security Advisories
2006-Dec-06 01:33 UTC
[FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-06:25.kmem
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================FreeBSD-SA-06:25.kmem Security Advisory The FreeBSD Project Topic: Kernel memory disclosure in firewire(4) Category: core Module: sys_dev Announced: 2006-12-06 Credits: Rodrigo Rubira Branco Affects: All FreeBSD releases. Corrected: 2006-12-06 09:13:51 UTC (RELENG_6, 6.2-STABLE) 2006-12-06 09:14:23 UTC (RELENG_6_2, 6.2-RC2) 2006-12-06 09:14:59 UTC (RELENG_6_1, 6.1-RELEASE-p11) 2006-12-06 09:15:40 UTC (RELENG_6_0, 6.0-RELEASE-p16) 2006-12-06 09:16:17 UTC (RELENG_5, 5.5-STABLE) 2006-12-06 09:16:41 UTC (RELENG_5_5, 5.5-RELEASE-p9) 2006-12-06 09:17:09 UTC (RELENG_4, 4.11-STABLE) 2006-12-06 09:18:02 UTC (RELENG_4_11, 4.11-RELEASE-p26) CVE Name: CVE-2006-6013 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/>. I. Background The firewire(4) driver provides support for IEEE 1394 ("FireWire") interfaces. This driver provides some of its functionality via the ioctl(2) system call. II. Problem Description In the FW_GCROM ioctl, a signed integer comparison is used instead of an unsigned integer comparison when computing the length of a buffer to be copied from the kernel into the calling application. III. Impact A user in the "operator" group can read the contents of kernel memory. Such 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 without IEEE 1394 ("FireWire") interfaces are not vulnerable. (Note that systems with IEEE 1394 interfaces are affected regardless of whether any devices are attached.) Note also that FreeBSD does not have any non-root users in the "operator" group by default; systems on which no users have been added to this group are therefore also not vulnerable. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to 4-STABLE, 5-STABLE, or 6-STABLE, or to the RELENG_6_1, RELENG_6_0, RELENG_5_5, or RELENG_4_11 security branch dated after the correction date. 2) To patch your present system: The following patches have been verified to apply to FreeBSD 4.11, 5.5, 6.0, and 6.1 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-06:25/kmem.patch # fetch http://security.FreeBSD.org/patches/SA-06:25/kmem.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. VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. Branch Revision Path - ------------------------------------------------------------------------- RELENG_4 src/sys/dev/firewire/fwdev.c 1.2.4.17 RELENG_4_11 src/UPDATING 1.73.2.91.2.27 src/sys/conf/newvers.sh 1.44.2.39.2.30 src/sys/dev/firewire/fwdev.c 1.2.4.16.4.1 RELENG_5 src/sys/dev/firewire/fwdev.c 1.44.2.2 RELENG_5_5 src/UPDATING 1.342.2.35.2.9 src/sys/conf/newvers.sh 1.62.2.21.2.11 src/sys/dev/firewire/fwdev.c 1.44.2.1.4.1 RELENG_6 src/sys/dev/firewire/fwdev.c 1.46.2.2 RELENG_6_2 src/UPDATING 1.416.2.29.2.1 src/sys/dev/firewire/fwdev.c 1.46.2.1.6.1 RELENG_6_1 src/UPDATING 1.416.2.22.2.13 src/sys/conf/newvers.sh 1.69.2.11.2.13 src/sys/dev/firewire/fwdev.c 1.46.2.1.4.1 RELENG_6_0 src/UPDATING 1.416.2.3.2.21 src/sys/conf/newvers.sh 1.69.2.8.2.17 src/sys/dev/firewire/fwdev.c 1.46.2.1.2.1 - ------------------------------------------------------------------------- VII. References http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6013 The latest revision of this advisory is available at http://security.FreeBSD.org/advisories/FreeBSD-SA-06:25.kmem.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFFdo1QFdaIBMps37IRAj4vAJ4vzhNk4MBkhAxsmeIAA0UgnXXOwACfY+Oe WhWIJLjTgqq+T3ZpySyRCNo=FbZj -----END PGP SIGNATURE-----