Vulnerability Note VU#820427

Microsoft Hyperlink Object Library buffer overflow

Original Release date: 08 Feb 2005 | Last revised: 08 Feb 2005


A buffer overflow exists in the Microsoft Windows system library used when handling hyperlinks. All currently supported versions of Microsoft Windows are affected.


An unchecked buffer in the Microsoft Object Library is vulnerable to attack when malformed hyperlinks are handled. Such handling occurs most often when a user clicks on a hyperlink in a browser or in HTML-rendered email.

The Object Library is a dynamic application interface library used by Windows programs to manage hyperlink objects. Hyperlink objects are any COM objects (including ActiveX) that implement the IHlink interface.


An attacker could execute arbitrary code of their choosing on the system running the vulnerable version of Windows. Upon successful exploitation, the malicious code would be executed with the privileges of the user being attacked.


Apply a patch from the vendor

Microsoft has published Microsoft Security Bulletin MS05-015 in response to this issue. Users are encouraged to review this bulletin and apply the patches it refers to.


As noted in Microsoft Security Bulletin MS05-015:

Read e-mail messages in plain text format if you are using Outlook 2002 or a later version, or Outlook Express 6 SP1 or a later version, to help protect yourself from the HTML e-mail attack vector.

Note that an email-borne attack vector requires a click event on a hyperlink to occur.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected-08 Feb 2005
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Microsoft has acknowledged Anna Hollingzworth as the discoverer of this vulnerability.

This document was written by Jeffrey S Havrilla.

Other Information

  • CVE IDs: CAN-2005-0057
  • Date Public: 08 Feb 2005
  • Date First Published: 08 Feb 2005
  • Date Last Updated: 08 Feb 2005
  • Severity Metric: 55.28
  • Document Revision: 10


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