Public Vulnerability Reports

Microsoft Word 2000 and Word 2002 Font Parsing Buffer Overflow Vulnerability



Microsoft Word is the word processing component of the Microsoft Office package.
More information can be found at the following link:


Remote exploitation of a buffer overflow vulnerability in Microsoft
Corp.'s Word could allow execution of arbitrary code.

A specially crafted .doc file, containing long font information, can
cause Word to overwrite stack space.

No checks are made on the length of data being copied, allowing the
return address on the stack to be overwritten.


Successful exploitation allows remote attackers to execute arbitrary
code in the context of the target user that opened the malicious
document. The data that is written onto the stack is in the form
"00xx00yy", where "xx" and "yy" are controlled by the input. While this
tends to make exploitation more difficult, it does not prevent it, as it
may be possible for an attacker to cause controlled data to be put into
a memory location matching the required format.


iDEFENSE Labs has confirmed that Microsoft Word 2002 is vulnerable.
Additionally, Microsoft has confirmed that Word 2000 is vulnerable.

Microsoft Word 2003 is not vulnerable to this issue.


User awareness is the best method of defense against this class of
attack. Users must be wary when opening files from untrusted sources.

When possible, run client software, as regular user accounts with
limited access to system resources. This may limit the immediate
consequences of client-side vulnerabilities.


The vendor security advisory and appropriate patches are available at:


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-0564 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


03/24/2005   Initial vendor notification
03/24/2005   Initial vendor response
07/12/2005   Coordinated public disclosure


Lord Yup is credited with this discovery.

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Copyright © 2005 Verisign, Inc.

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