3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
104 lines
3.5 KiB
Text
104 lines
3.5 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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Hash: SHA1
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=============================================================================
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FreeBSD-SA-04:15.syscons Security Advisory
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The FreeBSD Project
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Topic: Boundary checking errors in syscons
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Category: core
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Module: sys_dev_syscons
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Announced: 2004-10-04
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Credits: Christer Oberg
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Affects: FreeBSD 5.x releases
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Corrected: 2004-09-30 17:49:15 UTC (RELENG_5, 5.3-BETA6)
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2004-10-04 17:04:25 UTC (RELENG_5_2, 5.2.1-RELEASE-p11)
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CVE Name: CAN-2004-0919
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FreeBSD only: YES
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For general information regarding FreeBSD Security Advisories,
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including descriptions of the fields above, security branches, and the
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following sections, please visit
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<URL:http://www.freebsd.org/security/>.
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I. Background
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syscons(4) is the default console driver for FreeBSD. Using the
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physical keyboard and screen, it provides multiple virtual terminals
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which appear as if they were separate terminals. One virtual terminal
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is considered current and exclusively occupies the screen and the
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keyboard; the other virtual terminals are placed in the background.
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II. Problem Description
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The syscons CONS_SCRSHOT ioctl(2) does insufficient validation of
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its input arguments. In particular, negative coordinates or large
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coordinates may cause unexpected behavior.
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III. Impact
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It may be possible to cause the CONS_SCRSHOT ioctl to return portions of
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kernel memory. Such memory might contain sensitive information, such as
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portions of the file cache or terminal buffers. This information might
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be directly useful, or it might be leveraged to obtain elevated
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privileges in some way. For example, a terminal buffer might include a
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user-entered password.
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IV. Workaround
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There is no known workaround. However, this bug is only exploitable
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by users who have access to the physical console or can otherwise open
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a /dev/ttyv* device node.
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V. Solution
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Perform one of the following:
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1) Upgrade your vulnerable system to the RELENG_5_2 security branch
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dated after the correction date.
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2) To patch your present system:
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The following patches have been verified to apply to FreeBSD 5.2
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systems.
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a) Download the relevant patch from the location below, and verify the
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detached PGP signature using your PGP utility.
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# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:15/syscons.patch
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# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:15/syscons.patch.asc
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b) Apply the patch.
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# cd /usr/src
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# patch < /path/to/patch
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c) Recompile your kernel as described in
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<URL:http://www.freebsd.org/handbook/kernelconfig.html> and reboot the
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system.
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VI. Correction details
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The following list contains the revision numbers of each file that was
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corrected in FreeBSD.
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Branch Revision
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Path
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- -------------------------------------------------------------------------
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RELENG_5_2
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src/UPDATING 1.282.2.19
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src/sys/conf/newvers.sh 1.56.2.18
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src/sys/dev/syscons/syscons.c 1.409.2.1
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- -------------------------------------------------------------------------
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VII. References
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<URL:http://cvsweb.freebsd.org/src/sys/dev/syscons/syscons.c.diff?r1=1.428&r2=1.429>
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