X.Org X11 PCF font buffer overflow

xorg-pcffont-bo (39767)

High Risk

Description:

X.Org X11 is vulnerable to a buffer overflow, caused by improper bounds checking by the X server when handling PCF fonts. By sending a specially-crafted PCF font with a PCF_BDF_ENCODINGS table containing a difference between the "last col" and "first col" that is more than 255, a remote attacker could exploit this vulnerability to overflow a buffer and execute arbitrary code on the system with X server privileges or cause a denial of service.

Platforms Affected:

• Apple, Mac OS X 10.4.11
• Apple, Mac OS X 10.5.2
• Apple, Mac OS X Server 10.4.11
• Apple, Mac OS X Server 10.5.2
• Avaya, CMS R12
• Avaya, CMS R13/R13.1
• Avaya, CMS R14
• Avaya, IR 2.0
• Avaya, IR 3.0
• Canonical, Ubuntu 6.06 LTS
• Canonical, Ubuntu 6.10
• Canonical, Ubuntu 7.04
• Canonical, Ubuntu 7.10
• Debian, Debian Linux 3.1
• Debian, Debian Linux 4.0
• Gentoo, Linux
• IBM, AIX 5.2
• IBM, AIX 5.3
• IBM, AIX 6.1
• Mandriva, Corporate Server 3.0 X86_64
• Mandriva, Corporate Server 3.0
• Mandriva, Corporate Server 4.0 X86_64
• Mandriva, Corporate Server 4.0
• Mandriva, Linux 2007
• Mandriva, Linux 2007 X86_64
• Mandriva, Linux 2007.1
• Mandriva, Linux 2007.1 X86_64
• Mandriva, Linux 2008.0
• Mandriva, Linux 2008.0 X86_64
• Novell, Linux Desktop 9
• Novell, Linux POS 9
• Novell, Open Enterprise Server
• Novell, Open Enterprise Server
• Novell, OpenSUSE 10.2
• Novell, OpenSUSE 10.3
• Novell, SLE SDK 10 SP1
• Novell, SUSE Linux Enterprise Desktop 10 SP1
• Novell, SUSE Linux Enterprise Server 10
• Novell, SUSE Linux Enterprise Server 10 SP1
• RedHat, Enterprise Linux 2.1 ES
• RedHat, Enterprise Linux 2.1 WS
• RedHat, Enterprise Linux 2.1 AS
• RedHat, Enterprise Linux 3 Desktop
• RedHat, Enterprise Linux 3 WS
• RedHat, Enterprise Linux 3 ES
• RedHat, Enterprise Linux 3 AS
• RedHat, Enterprise Linux 4 WS
• RedHat, Enterprise Linux 4 ES
• RedHat, Enterprise Linux 4 Desktop
• RedHat, Enterprise Linux 4 AS
• RedHat, Enterprise Linux 5
• RedHat, Enterprise Linux 5 Client Workstation
• RedHat, Enterprise Linux 5 Client
• RedHat, Linux Advanced Workstation 2.1 Itanium
• Sun, Solaris 10 SPARC
• Sun, Solaris 10 x86
• Sun, Solaris 8.0 SPARC
• Sun, Solaris 8.0 x86
• Sun, Solaris 9.0 SPARC
• Sun, Solaris 9.0 x86
• SuSE, SLE SDK 10
• SuSE, SuSE Linux 9.0
• SuSE, SuSE SLES 9
• X.Org, X.Org X11 R7.3 and prior

Remedy:

Upgrade to the latest version of X.Org X11 (1.4 or later), available from the X.Org Foundation Web site. See References.

For Sun Solaris:
Refer to Sun Alert ID: 103192 for patch, upgrade, or suggested workaround information. See References.

For Mac OS X:
Apply Security Update 2008-002, available from the Apple Web site. See References.

For other distributions:
Apply the appropriate update for your system. See References.

Consequences:

Gain Access

References:

• Apple Web site, About Security Update 2008-002 at http://docs.info.apple.com/article.html?artnum=307562.
• ASA-2008-077, A Security Vulnerability in the Solaris X Window System (X(5)) PCF Font Handler May Lead to Execution of Arbitrary Code or a Denial of Service (DoS) Condition at http://support.avaya.com/elmodocs2/security/ASA-2008-077.htm.
• ASA-2008-078, Multiple Security Vulnerabilities in the Solaris X Server Extensions May Lead to a Denial of Service (DoS) Condition or Allow Execution of Arbitrary Code at http://support.avaya.com/elmodocs2/security/ASA-2008-078.htm.
• IBM Subscription service Bulletin 4136, AIX X server multiple vulnerabilities at http://www14.software.ibm.com/webapp/set2/subscriptions/ijhifoeblist?mode=7&heading=AIX61&path=/200802/SECURITY/20080227/datafile112539&label=AIX%20X%20server%20multiple%20vulnerabilities.
• Sun Alert ID: 103192, A Security Vulnerability in the Solaris X Window System (X(5)) PCF Font Handler May Lead to Execution of Arbitrary Code or a Denial of Service (DoS) Condition at http://sunsolve.sun.com:80/search/document.do?assetkey=1-26-103192-1.
• X.Org Foundation Web site, X.Org Wiki - Home at http://xorg.freedesktop.org/wiki/Home.
• X.Org Mailing List, Thu Jan 17 06:05:34 PST 2008, X.Org security advisory: multiple vulnerabilities in the X server at http://lists.freedesktop.org/archives/xorg/2008-January/031918.html.
• ASA-2008-035: XFree86 security update (RHSA-2008-0029)
• ASA-2008-036: xorg-x11 security update (RHSA-2008-0030)
• ASA-2008-038: A Security Vulnerability in the Solaris X Window System (X(5)) PCF Font Handler May Lead to Execution of Arbitrary Code or a Denial of Service (DoS) Condit
• ASA-2008-077: A Security Vulnerability in the Solaris X Window System (X(5)) PCF Font Handler May Lead to Execution of Arbitrary Code or a Denial of Service (DoS) Condition (Sun 201230)
• BID-27336: RETIRED: X.Org X Server Local Privilege Escalation and Information Disclosure Vulnerabilities
• BID-27352: X.Org X Server PCF Font Parser Buffer Overflow Vulnerability
• CVE-2008-0006: Buffer overflow in (1) X.Org Xserver before 1.4.1, and (2) the libfont and libXfont libraries on some platforms including Sun Solaris, allows context-dependent attackers to execute arbitrary code via a PCF font with a large difference between the last col and first col values in the PCF_BDF_ENCODINGS table.
• DSA-1466: xorg-server -- several vulnerabilities
• FrSIRT/ADV-2008-0179: X.Org X11 Integer Overflow and Memory Corruption Vulnerabilities
• FrSIRT/ADV-2008-0184: Sun Solaris X Windows Integer Overflow and Memory Corruption Issues
• FrSIRT/ADV-2008-0497: NoMachine NX Server Security Update Fixes X11 Multiple Vulnerabilities
• FrSIRT/ADV-2008-0703: IBM AIX Privilege Escalation and Remote Code Execution Vulnerabilities
• FrSIRT/ADV-2008-0924: Apple Mac OS X Command Execution and Security Bypass Issues
• GLSA-200801-09: X.Org X server and Xfont library: Multiple vulnerabilities
• MDVSA-2008:021: Updated XFree86 packages fix multiple vulnerabilities
• MDVSA-2008:022: Updated xorg-x11 packages fix multiple vulnerabilities
• MDVSA-2008:024: Updated libxfont packages fix font handling vulnerability
• RHSA-2008-0029: Important: XFree86 security update
• RHSA-2008-0030: Important: xorg-x11 security update
• RHSA-2008-0064: Important: libXfont security update
• SA28532: X.org X11 Multiple Vulnerabilities
• SA28550: Sun Solaris X Window System and X Server Multiple Vulnerabilities
• SA28621: Avaya CMS / IR Solaris X Window System PCF Font Handler Vulnerability
• SA28885: NX Server X11 Multiple Vulnerabilities
• SA28941: Avaya CMS Sun Solaris X Window System and X Server Vulnerabilities
• SA29139: IBM AIX X Server Multiple Vulnerabilities
• SA29420: Mac OS X Security Update Fixes Multiple Vulnerabilities
• SA30161: Gentoo ltsp Multiple Vulnerabilities
• SECTRACK ID: 1019232: X Server Bugs in XFree86, Xinput, TOG-CUP, MIT-SHM, and EVI Extensions Let Local Users Gain Root Privileges
• SUSE-SA:2008:003: Xorg Security Problems
• SUSE-SR:2008:008: SUSE Security Summary Advisory
• US-CERT VU#203220: X.Org PCF font parser buffer overflow
• USN-571-1: X.org vulnerabilities
• USN-571-2: X.org regression

Reported:

Jan 17, 2008

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

Copyright (c) 1994-2008 Internet Security Systems, Inc. All rights reserved worldwide.

For corrections or additions please email xforce@iss.net

Return to the main page