Secunia

A vulnerability has been reported in Skype, which can be exploited by malicious people to bypass certain security restrictions and potentially disclose certain sensitive information.

The vulnerability is caused due to an error within the parsing of the parameters passed by the URI handler. This can be exploited to inject a malicious "/Datapath" argument pointing to e.g. a malicious remote SMB share, which can be leveraged to e.g. control certain Skype settings (e.g. security policy or proxy settings) and gain access to sensitive information (e.g. chat logs and call history).

Successful exploitation requires that a Skype user is tricked into clicking a specially crafted "skype:" URI and may also depend on the browser being used. Internet Explorer 6, 7, or 8 and Chrome are reported as possible vectors.

The vulnerability is reported in all versions prior to version 4.2.0.1.55 (v4.2 hotfix #1) for Windows.

Solution
Update to version 4.2.0.1.55 (v4.2 hotfix #1).

Provided and/or discovered by
* Paul Craig, Security-Assessment.com Ltd.
* Independently reported by Anonymous via ZDI.

Changelog
Further details available in Customer Area

Original Advisory
Security-Assessment.com Ltd:
http://www.security-assessment.com/files/advisories/Skype_URI_Handling_Vulnerability.pdf

Skype Release notes:
https://developer.skype.com/WindowsSkype/ReleaseNotes
http://share.skype.com/sites/garage/2010/03/10/ReleaseNotes_4.2.0.155.pdf

ZDI:
http://www.zerodayinitiative.com/advisories/ZDI-10-027/

Deep Links
Links available in Customer Area