__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Linux mremap(2) System Call Vulnerability [Debian Security Advisory DSA-456-1] March 8, 2004 20:00 GMT Number O-094 [REVISED 19 Mar 2004] [REVISED 01 Apr 2004] [REVISED 06 Apr 2004] [REVISED 04 Jun 2004] ______________________________________________________________________________ PROBLEM: A security vulnerability exists in the memory management code of Linux inside the mremap(2) system call. PLATFORM: Debian GNU/Linux 3.0 (woody) - kernel-2.2.20 - all platforms - kernel-2.2.19 - all platforms - kernel-2.4.17-hppa - kernel-2.4.18-hppa - kernel-2.2.10 - powerpc-apus - kernel-image-sparc-2.2 DAMAGE: Due to flushing the Translation Lookaside Buffer too early, it is possible for an unprivileged user to trigger a local root exploit. SOLUTION: Upgrade your Linux kernel package. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. A local unprivileged user may gain root ASSESSMENT: privileges. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/o-094.shtml ORIGINAL BULLETIN: Debian Security Advisory DSA-456 http://www.debian.org/security/2004/dsa-456 ADDITIONAL LINKS: Debian Security Advisories: http://www.debian.org/security/2004/dsa-453 http://www.debian.org/security/2004/dsa-466 http://www.debian.org/security/2004/dsa-470 http://www.debian.org/security/2004/dsa-475 http://www.debian.org/security/2004/dsa-475 CVE/CAN: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2004-0077 ______________________________________________________________________________ REVISION HISTORY: 03/19/04 - Added a link to Debian Security Advisory 466-1 linux-kernel-2.2.10-powerpc-apus updated packages. 04/01/04 - Added a link to Debian Security Advisory 470-1 linux-kernel-2.4.17-hppa for an upgrade package. 04/06/04 - Added a link to Debian Security Advisory 475-1 linux-kernel-2.4.18-hppa for an upgrade package. 06/04/04 - added a link to Debian Security Advisory 514-1, for an upgrade fixing kernel-image-sparc-2.2. [***** Start Debian Security Advisory DSA-456-1 *****] Debian Security Advisory DSA-456-1 linux-kernel-2.2.19-arm -- failing function and TLB flush Date Reported: 06 Mar 2004 Affected Packages: kernel-source-2.2.19 kernel-patch-2.2.19-arm kernel-image-2.2.19-netwinder kernel-image-2.2.19-riscpc Vulnerable: Yes Security database references: In Mitre's CVE dictionary: CAN-2004-0077. More information: Paul Starzetz and Wojciech Purczynski of isec.pl discovered a critical security vulnerability in the memory management code of Linux inside the mremap(2) system call. Due to flushing the TLB (Translation Lookaside Buffer, an address cache) too early it is possible for an attacker to trigger a local root exploit. The attack vectors for 2.4.x and 2.2.x kernels are exclusive for the respective kernel series, though. We formerly believed that the exploitable vulnerability in 2.4.x does not exist in 2.2.x which is still true. However, it turned out that a second (sort of) vulnerability is indeed exploitable in 2.2.x, but not in 2.4.x, with a different exploit, of course. For the stable distribution (woody) this problem has been fixed in version 20040303 of 2.2 kernel images for the arm architecture. For the unstable distribution (sid) this problem will be fixed soon for the architectures that still ship a 2.2.x kernel package. We recommend that you upgrade your Linux kernel package. Fixed in: Debian GNU/Linux 3.0 (woody) Source: http://master.debian.org/~joey/stuff/2.2.19/kernel-source-2.2.19_2.2.19.1-4 woody1.diff.gz http://master.debian.org/~joey/stuff/2.2.19/kernel-source-2.2.19_2.2.19.1-4 woody1.dsc http://master.debian.org/~joey/stuff/2.2.19/kernel-source-2.2.19_2.2.19.1.orig.tar.gz http://security.debian.org/pool/updates/main/k/kernel-patch-2.2.19-arm/kernel- patch-2.2.19-arm_20040303.dsc http://security.debian.org/pool/updates/main/k/kernel-patch-2.2.19-arm/kernel- patch-2.2.19-arm_20040303.tar.gz http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-netwinder/kernel- image-2.2.19-netwinder_20040303.dsc http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-netwinder/kernel- image-2.2.19-netwinder_20040303.tar.gz http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-riscpc/kernel- image-2.2.19-riscpc_20040303.dsc http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-riscpc/kernel- image-2.2.19-riscpc_20040303.tar.gz Architecture-independent component: http://master.debian.org/~joey/stuff/2.2.19/kernel-doc-2.2.19_2.2.19.1-4woody1_all.deb http://master.debian.org/~joey/stuff/2.2.19/kernel-source-2.2.19_2.2.19.1-4woody1_all.deb http://security.debian.org/pool/updates/main/k/kernel-patch-2.2.19-arm/kernel-patch- 2.2.19-arm_20040303_all.deb ARM: http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-netwinder/kernel- headers-2.2.19_20040303_arm.deb http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-netwinder/kernel- image-2.2.19-netwinder_20040303_arm.deb http://security.debian.org/pool/updates/main/k/kernel-image-2.2.19-riscpc/kernel- image-2.2.19-riscpc_20040303_arm.deb MD5 checksums of the listed files are available in the original advisory. [***** End Debian Security Advisory DSA-456-1 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Debian for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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