[ GLSA 200801-09 ] X.Org X server and Xfont library: Multiple vulnerabilities

[GLSA]

Gentoo Linux Security Advisory

Title: X.Org X server and Xfont library: Multiple vulnerabilities (GLSA 200801-09)
Severity: high
Exploitable: remote, local
Date: January 20, 2008
Updated: March 05, 2008
Bug(s): #204362, #208343
ID: 200801-09

Synopsis

Multiple vulnerabilities have been discovered in the X.Org X server and Xfont library, allowing for a local privilege escalation and arbitrary code execution.

Background

The X Window System is a graphical windowing system based on a client/server model.

Affected Packages

Package: x11-base/xorg-server
Vulnerable: < 1.3.0.0-r5
Unaffected: >= 1.3.0.0-r5
Architectures: All supported architectures

Package: x11-libs/libXfont
Vulnerable: < 1.3.1-r1
Unaffected: >= 1.3.1-r1
Architectures: All supported architectures


Description

regenrecht reported multiple vulnerabilities in various X server extension via iDefense:

• The XFree86-Misc extension does not properly sanitize a parameter within a PassMessage request, allowing the modification of a function pointer (CVE-2007-5760).
• Multiple functions in the XInput extension do not properly sanitize client requests for swapping bytes, leading to corruption of heap memory (CVE-2007-6427).
• Integer overflow vulnerabilities in the EVI extension and in the MIT-SHM extension can lead to buffer overflows (CVE-2007-6429).
• The TOG-CUP extension does not sanitize an index value in the ProcGetReservedColormapEntries() function, leading to arbitrary memory access (CVE-2007-6428).
• A buffer overflow was discovered in the Xfont library when processing PCF font files (CVE-2008-0006).
• The X server does not enforce restrictions when a user specifies a security policy file and attempts to open it (CVE-2007-5958).

Impact

Remote attackers could exploit the vulnerability in the Xfont library by enticing a user to load a specially crafted PCF font file resulting in the execution of arbitrary code with the privileges of the user running the X server, typically root. Local attackers could exploit this and the vulnerabilities in the X.org extensions to gain elevated privileges. If the X server allows connections from the network, these vulnerabilities could be exploited remotely. A local attacker could determine the existence of arbitrary files by exploiting the last vulnerability or possibly cause a Denial of Service.

Workaround

Workarounds for some of the vulnerabilities can be found in the X.Org security advisory as listed under References.

Resolution

All X.Org X server users should upgrade to the latest version: