User interaction is required to exploit this vulnerability in that the target must visit a malicious page.
The specific flaw exists with how the OS web-browser passes command line arguments to Skype through the registered 'skype:' protocol handler. Insufficient sanity checking to the /datapath argument allows an attacker to construct a link that will execute Skype with arbitrary arguments. This can be abused to specify a remote configuration storage directory which can be leveraged to glean target user credentials.
Patch Availability:
Skype has issued an update to correct this vulnerability. More details can be found at:
http://share.skype.com/sites/garage/2010/03/10/ReleaseNotes_4.2.0.155.pdf
Disclosure Timeline:
2009-07-14 - Initial report to vendor, no response.
2010-01-11 - Received support e-mail with update notice from Skype.
2010-01-19 - We followed up with Skype again who has not been heard from since.
2010-03-11 - Uncoordinated release of public advisory due to overlap with Paul Craig issue is resolved in latest version of Skype.
