Technical Description

Multiple vulnerabilities have been idenitified in X.Org X11 Server, which could be exploited by attackers to cause a denial of service or execute arbitrary code.

The first issue is caused by integer overflow errors within the handlers for the "QueryXBitmaps" and "QueryXExtents" protocol requests when calling the "build_range()" function, which could be exploited by attackers to cause a heap overflow and compromise a vulnerable system via a specially crafted request.

The second vulnerability is caused by memory corruption errors within the handlers for the "QueryXBitmaps" and "QueryXExtents" protocol requests when calling the "swap_char2b()" function, which could be exploited by attackers to swap an arbitrary number of bytes on the heap.

Affected Products

X.Org xfs version 1.0.4 (X11R7.3) and prior

Solution

Upgrade to X.Org XFS version 1.0.5 :
ftp://ftp.freedesktop.org/pub/

Apply patch :
ftp://ftp.freedesktop.org/pub/X11R7.3/patches/xorg-xfs-1.0.4-query.diff

References

http://www.vupen.com/english/advisories/2007/3337
http://lists.freedesktop.org/archives/xorg-announce/2007-October/000416.html
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=602

Credits

Vulnerabilities reported by Sean Larsson (VeriSign iDefense Labs).

ChangeLog

2007-10-03 : Initial release

Vulnerability Management

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