Multiple Vendor X Font Server DoS and Buffer Overflow Vulnerabilities

Bugtraq ID:	1111
Class:	Boundary Condition Error
CVE:	CVE-2000-0263 CVE-2000-0286
Remote:	No
Local:	Yes
Published:	Apr 16 2000 12:00AM
Updated:	Jul 11 2009 01:56AM
Credit:	This vulnerability was posted to the Bugtraq mailing list on April 16, 2000 by Michal Zalewski <[email protected]>
Vulnerable:	Redhat Linux 6.2 sparc Redhat Linux 6.2 i386 Redhat Linux 6.2 alpha Redhat Linux 6.1 sparc Redhat Linux 6.1 i386 Redhat Linux 6.1 alpha Redhat Linux 6.0 sparc Redhat Linux 6.0 alpha Redhat Linux 6.0
Not Vulnerable:

Multiple Vendor X Font Server DoS and Buffer Overflow Vulnerabilities

A denial of service exists in the X11 font server shipped with RedHat Linux 6.x. Due to improper input validation, it is possible for any user to crash the X fontserver. This will prevent the X server from functioning properly.

Additional, similar problems exist in the stock xfs. Users can crash the font server remotely, and potential exists for buffer overruns. The crux of the problem stems from the font server being lax about verifying network input. While no exploits exist, it is likely they are available in private circles, and can result in remote root compromise.

Multiple Vendor X Font Server DoS and Buffer Overflow Vulnerabilities

An exploit has been made available.

• /data/vulnerabilities/exploits/kill-xfs.c

Multiple Vendor X Font Server DoS and Buffer Overflow Vulnerabilities

Solution:
Currently the SecurityFocus staff are not aware of any vendor supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].

Multiple Vendor X Font Server DoS and Buffer Overflow Vulnerabilities

References: