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Skype URI handling routine contains a buffer overflow

Vulnerability Note VU#930345

Original Release Date: 2005-10-26 | Last Revised: 2005-10-26


A buffer overflow in Skype may allow a remote attacker to execute code on a vulnerable system.


Skype software provides telephone service over IP networks. There is a buffer overflow in the routines that handle Skype-specific URIs (callto:// or skype://). The buffer overflow may stem from an input validation error in the Delphi routine SysUtils.WideFmtStr(...).

For more information, please see Skype Security Bulletin SKYPE-SB/2005-002 and Delphi Bug Report 4744.


A remote attacker may be able to execute arbitrary code if they can persuade a user to access a Skype-specific URI with a vulnerable Skype installation.


Upgrade Skype
Please see Skype Security Bulletin SKYPE-SB/2005-002 for a list of fixed Skype versions.

Do not access Skype URIs from untrusted sources

Exploitation occurs by accessing a specially crafted Skype URIs. By only accessing a Skype URIs from trusted or known sources, the chances of exploitation are reduced.

Vendor Information


Skype Technologies Affected

Updated:  October 26, 2005



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


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If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

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



This vulnerability was reported by SKY-CERT. SKY-CERT credits Mark Rowe of Pentest Limited with providing information regarding this issue.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2005-3265
Severity Metric: 10.13
Date Public: 2005-10-25
Date First Published: 2005-10-26
Date Last Updated: 2005-10-26 16:49 UTC
Document Revision: 14

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