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Subject: [FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-05:07.ldt
From: FreeBSD Security Advisories <
Date: Fri, 6 May 2005 03:03:13 GMT
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-05:07.ldt Security Advisory The FreeBSD Project Topic: Local kernel memory disclosure in i386_get_ldt Category: core Module: sys_i386 Announced: 2005-05-06 Credits: Christer Oberg Affects: All FreeBSD/i386 4.x releases since 4.7-RELEASE All FreeBSD/i386 5.x and FreeBSD/amd64 5.x releases prior to 5.4-RELEASE Corrected: 2005-05-06 02:40:19 UTC (RELENG_5, 5.4-STABLE) 2005-05-06 02:40:49 UTC (RELENG_5_4, 5.4-RELEASE) 2005-05-06 02:40:32 UTC (RELENG_5_3, 5.3-RELEASE-p12) 2005-05-06 02:39:35 UTC (RELENG_4, 4.11-STABLE) 2005-05-06 02:40:05 UTC (RELENG_4_11, 4.11-RELEASE-p6) 2005-05-06 02:39:52 UTC (RELENG_4_10, 4.10-RELEASE-p11) CVE Name: CAN-2005-1400 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://www.freebsd.org/security/>. I. Background The i386_get_ldt(2) system call allows a process to request that a portion of its Local Descriptor Table be copied from the kernel into userland. II. Problem Description The i386_get_ldt(2) syscall performs insufficient validation of its input arguments. In particular, negative or very large values may allow inappropriate data to be copied from the kernel. III. Impact Kernel memory may be disclosed to the user process. 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 known for i386 and amd64 systems; other platforms are not affected by this issue. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to 4-STABLE or 5-STABLE, or to the RELENG_5_3, RELENG_4_11, or RELENG_4_10 security branch dated after the correction date. 2) To patch your present system: The following patches have been verified to apply to FreeBSD 4.10, 4.11, and 5.3 systems. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 4.x] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:07/ldt4.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:07/ldt4.patch.asc [FreeBSD 5.x] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:07/ldt5.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:07/ldt5.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/i386/i386/sys_machdep.c 1.47.2.4 RELENG_4_11 src/UPDATING 1.73.2.91.2.7 src/sys/conf/newvers.sh 1.44.2.39.2.10 src/sys/i386/i386/sys_machdep.c 1.47.2.3.8.1 RELENG_4_10 src/UPDATING 1.73.2.90.2.12 src/sys/conf/newvers.sh 1.44.2.34.2.13 src/sys/i386/i386/sys_machdep.c 1.47.2.3.6.1 RELENG_5 src/sys/i386/i386/sys_machdep.c 1.92.2.3 RELENG_5_4 src/UPDATING 1.342.2.24.2.6 src/sys/i386/i386/sys_machdep.c 1.92.2.1.2.1 RELENG_5_3 src/UPDATING 1.342.2.13.2.15 src/sys/conf/newvers.sh 1.62.2.15.2.17 src/sys/i386/i386/sys_machdep.c 1.92.4.1 - ------------------------------------------------------------------------- The latest revision of this advisory is available at ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:07.ldt.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFCetz/FdaIBMps37IRAsGyAJ0e/186b85KV2w0iqXy+eZe4aoGMwCfSlRm TqqVUL/yrYbXxlyzJZNEjPs= =/YXX -----END PGP SIGNATURE----- _______________________________________________This email address is being protected from spambots. You need JavaScript enabled to view it. mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "This email address is being protected from spambots. You need JavaScript enabled to view it. "
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