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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2007.0701 -- [NetBSD] Local panics in display driver code 14 September 2007 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: kernel Publisher: NetBSD Operating System: NetBSD Impact: Denial of Service Access: Existing Account CVE Names: CVE-2007-3654 Original Bulletin: ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2007-006.txt.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NetBSD Security Advisory 2007-006 ================================= Topic: Local panics in display driver code Version: NetBSD-current: source prior to July 28, 2007 NetBSD 4.0_BETA2 affected NetBSD 3.1: affected NetBSD 3.0.*: affected NetBSD 3.0: affected NetBSD 2.1: not affected NetBSD 2.0.*: not affected NetBSD 2.0: not affected Severity: Local system crash Fixed: NetBSD-current: July 28, 2007 NetBSD-4 branch: July 30, 2007 (4.0 will include the fix) NetBSD-3-1 branch August 6, 2007 (3.1.1 will include the fix) NetBSD-3-0 branch: August 6, 2007 (3.0.3 will include the fix) NetBSD-3 branch: August 6, 2007 Abstract ======== A local user can cause the system to panic by passing out of bounds values to display driver allocattr functions via an ioctl call. This vulnerability has been assigned CVE reference CVE-2007-3654. Technical Details ================= vga_allocattr uses integer arguments as indicies into arrays of colors. The vga_allocattr function does not check to see whether these arguments are within the bounds of the arrays. Due to the lack of bounds checking a negative or large value can be passed to vga_allocattr which will cause it to access arbitrary memory locations, resulting in a panic. Other display driver functions are also vulnerable to this issue. Solutions and Workarounds ========================= To rectify these problems a kernel built from sources containing the fixes must be installed and the system rebooted. The following instructions describe how to upgrade your kernel by updating your source tree and rebuilding and installing a new version of the kernel. For more information on how to do this, see: http://www.NetBSD.org/guide/en/chap-kernel.html * NetBSD-current: Systems running NetBSD-current dated from before 2007-07-28 should be upgraded to NetBSD-current dated 2007-07-29 or later. The following files need to be updated from the netbsd-current CVS branch (aka HEAD): sys/dev/ic/pcdisplay_subr.c sys/dev/ic/vga.c sys/dev/ic/vga_raster.c sys/dev/isa/ega.c sys/dev/pci/chipsfb.c sys/dev/rasops/rasops.c sys/dev/wscons/wsdisplay_vcons.c To update from CVS, re-build, and re-install a kernel containing the fix: # cd src # cvs update -d -P sys/dev # build.sh tools kernel=KERNCONFFILE * NetBSD 3.*: Systems running NetBSD 3.* sources dated from before 2007-08-06 should be upgraded from NetBSD 3.* sources dated 2007-08-07 or later. The following files need to be updated from the netbsd-3, netbsd-3-0 or netbsd-3-1 branches: sys/dev/ic/pcdisplay_subr.c sys/dev/ic/vga.c sys/dev/ic/vga_raster.c sys/dev/isa/ega.c sys/dev/rasops/rasops.c To update from CVS, re-build, and re-install a kernel containing the fix: # cd src # cvs update -r <branch_name> sys/dev/ic/pcdisplay_subr.c # cvs update -r <branch_name> sys/dev/ic/vga.c # cvs update -r <branch_name> sys/dev/ic/vga_raster.c # cvs update -r <branch_name> sys/dev/isa/ega.c # cvs update -r <branch_name> sys/dev/rasops/rasops.c # build.sh tools kernel=KERNCONFFILE Thanks To ========= Venustech AD-LAB for discovering and reporting this problem. Revision History ================ 2007-09-13 Initial release More Information ================ Advisories may be updated as new information becomes available. The most recent version of this advisory (PGP signed) can be found at ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2007-006.txt.asc Information about NetBSD and NetBSD security can be found at http://www.NetBSD.org/ and http://www.NetBSD.org/Security/. Copyright 2007, The NetBSD Foundation, Inc. All Rights Reserved. Redistribution permitted only in full, unmodified form. $NetBSD: rt14768_vga.txt,v 1.7 2007/08/14 21:59:52 adrianp Exp $ - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (NetBSD) iQCVAwUBRuhdST5Ru2/4N2IFAQJSJwP/flQbkGFFk0AUppV2f98co5RQbJQqsK7I KEBVenilE2LpgUscPRspYWsF6WKRvWgmyOS+7DlfaQ/1/+GjlcXnuJVfJ9CSHf28 iLHHPSK9FDi0IlpFgHq6FSzsoQu+KpaKmvCxLyAlpSn5apDZkBPzobgt/fI6x0Vh Uc9GnnDZPT0= =LsPT - -----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 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== 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 iQCVAwUBRuoTaih9+71yA2DNAQKhLQP/QWt1EQ8N3UyV5zw2d3Lo8EydeHFFojP7 SCmUi+ehg1tiuT8QgwFXOmkxQ3DouPk1URXR15VpTnQRMjFSdFl338n5paOgfHtV I6k54ff/h06T/ftlOZ9fWaU5nd3NS4PwL+gPCHwdVDTPPq1W43zAx2XL32W3X1Ee EJ7gnLb7ZbI= =Vs0n -----END PGP SIGNATURE-----