X.Org X server: Multiple vulnerabilities — GLSA 200806-07

Multiple vulnerabilities have been discovered in the X.Org X server, possibly allowing for the remote execution of arbitrary code with root privileges.

Affected packages

Package	x11-base/xorg-server on all architectures
Affected versions	< 1.3.0.0-r6
Unaffected versions	>= 1.3.0.0-r6

Background

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

Description

Regenrecht reported multiple vulnerabilities in various X server extensions via iDefense:

The SProcSecurityGenerateAuthorization() and SProcRecordCreateContext() functions of the RECORD and Security extensions are lacking proper parameter validation (CVE-2008-1377).
An integer overflow is possible in the function ShmPutImage() of the MIT-SHM extension (CVE-2008-1379).
The RENDER extension contains several possible integer overflows in the AllocateGlyph() function (CVE-2008-2360) which could possibly lead to a heap-based buffer overflow. Further possible integer overflows have been found in the ProcRenderCreateCursor() function (CVE-2008-2361) as well as in the SProcRenderCreateLinearGradient(), SProcRenderCreateRadialGradient() and SProcRenderCreateConicalGradient() functions (CVE-2008-2362).

Impact

Exploitation of these vulnerabilities could possibly lead to the remote execution of arbitrary code with root privileges, if the server is running as root, which is the default. It is also possible to crash the server by making use of these vulnerabilities.

Workaround

It is possible to avoid these vulnerabilities by disabling the affected server extensions. Therefore edit the configuration file (/etc/X11/xorg.conf) to contain the following in the appropriate places:


      Section "Extensions"   
    	Option "MIT-SHM" "disable"
    	Option "RENDER" "disable" 
    	Option "SECURITY" "disable"
      EndSection
    
      Section "Module"
       Disable "record"
      EndSection

Resolution

All X.org X Server users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.3.0.0-r6"

References

Release date
June 19, 2008

Latest revision
June 19, 2008: 01

Severity
high

Exploitable
remote, local

Bugzilla entries

225419