TippingPoint Zero Day Initiative

Skype URI Handler Remote Heap Corruption Vulnerability

ZDI-07-070: December 6th, 2007


Affected Vendors


Affected Products


TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 5752. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Skype. User interaction is required to exploit this vulnerability in that the target must visit a malicious page.

The specific flaw exists within the 'skype4com' URI handler created by Skype during installation. When processing short string values through this handler an exploitable memory corruption may occur which can result in arbitrary code execution under the context of the current user.

Vendor Response

Skype states:

Skype has corrected this issue as of 11/15/2007. All clients updated or installed as of that date are patched to this issue.

Disclosure Timeline

    2007-11-02 - Vulnerability reported to vendor
    2007-12-06 - Coordinated public release of advisory


This vulnerability was discovered by: