search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Skype vulnerable to heap-based buffer overflow

Vulnerability Note VU#905177

Original Release Date: 2005-10-26 | Last Revised: 2005-10-31


A heap-based buffer overflow in Skype may allow a remote attacker to execute arbitrary code or cause a denial-of-service condition.


Skype software provides telephone service over IP networks. Skype contains a buffer overflow in a routine that parses incoming network traffic. The issue exists because Skype relies on user-controlled data to determine the size of buffers used to handle incoming packets. This may allow a remote attacker to manipulate memory allocation routines to create an under-sized buffer. When data is copied to this buffer, a heap-based buffer overflow may occur.

For more information, please refer to Skype Security Bulletin SKYPE-SB/2005-003.


A remote attacker may be able to overwrite heap memory causing the Skype process to crash or cause unpredictable behavior. In addition, public reports claim this vulnerability can be used to execute arbitrary code.


Upgrade Skype
Please see Skype Security Bulletin SKYPE-SB/2005-003 for a list of fixed Skype versions.

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.


Please see

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

CVSS Metrics

Group Score Vector



This vulnerability was reported by SKY-CERT. Skype credits EADS Corporate Research Center security lab with providing information regarding this vulnerability.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2005-3267
Severity Metric: 20.88
Date Public: 2005-10-25
Date First Published: 2005-10-26
Date Last Updated: 2005-10-31 14:00 UTC
Document Revision: 18

Sponsored by CISA.