====================================================================== 

                     Secunia Research 09/05/2007

     - BearShare NCTAudioFile2 ActiveX Control Buffer Overflow -

====================================================================== 
Table of Contents

Affected Software....................................................1
Severity.............................................................2
Vendor's Description of Software.....................................3
Description of Vulnerability.........................................4
Solution.............................................................5
Time Table...........................................................6
Credits..............................................................7
References...........................................................8
About Secunia........................................................9
Verification........................................................10

====================================================================== 
1) Affected Software 

BearShare 6.0.2.26789

NOTE: Other versions may also be affected.

====================================================================== 
2) Severity 

Rating: Highly critical
Impact: System compromise
Where:  Remote

====================================================================== 
3) Vendor's Description of Software 

"Share, Discover and Download music and videos."

Product Link:
http://www.bearshare.com/

====================================================================== 
4) Description of Vulnerability

Secunia Research has discovered a vulnerability in BearShare, which 
can be exploited by malicious people to compromise a user's system.

The vulnerability is caused due to a boundary error in the
NCTAudioFile2.AudioFile ActiveX control when handling the
"SetFormatLikeSample()" method. This can be exploited to cause a 
stack-based buffer overflow by passing an overly long string (about 
4124 bytes) as argument to the affected method.

Successful exploitation allows execution of arbitrary code when a user
e.g. visits a malicious website.

====================================================================== 
5) Solution 

Set the kill-bit for the affected ActiveX control.

====================================================================== 
6) Time Table 

30/04/2007 - Vendor notified.
09/05/2007 - Public disclosure.

====================================================================== 
7) Credits 

Discovered by Carsten Eiram, Secunia Research.

====================================================================== 
8) References

The Common Vulnerabilities and Exposures (CVE) project has assigned 
CVE-2007-0018 for the vulnerability.

====================================================================== 
9) About Secunia

Secunia offers vulnerability management solutions to corporate
customers with verified and reliable vulnerability intelligence
relevant to their specific system configuration:

http://corporate.secunia.com/

Secunia also provides a publicly accessible and comprehensive advisory
database as a service to the security community and private 
individuals, who are interested in or concerned about IT-security.

http://secunia.com/

Secunia believes that it is important to support the community and to
do active vulnerability research in order to aid improving the 
security and reliability of software in general:

http://corporate.secunia.com/secunia_research/33/

Secunia regularly hires new skilled team members. Check the URL below
to see currently vacant positions:

http://secunia.com/secunia_vacancies/

Secunia offers a FREE mailing list called Secunia Security Advisories:

http://secunia.com/secunia_security_advisories/

====================================================================== 
10) Verification 

Please verify this advisory by visiting the Secunia website:
http://secunia.com/secunia_research/2007-50/

Complete list of vulnerability reports published by Secunia Research:
http://secunia.com/secunia_research/

======================================================================