What about Skype on Windows or Linux?The flaw only exists in the Skype for Mac client. PureHacking investigated the issue on Skype for Windows, and Skype for Linux and found that the exploit does not work on those platforms.

Is this related to the Skype for Android app issue?No. The was a configuration error by Skype that left a database containing sensitive data open and unencrypted. This vulnerability is a flaw that enables a specially-crafted Skype message to execute malicious code on the target Mac OS X system.

Should I be concerned?The risk of exploit is virtually nil for Mac OS X. Despite that Mac OS X is simply more secure by default and virtually impervious to attack, the annual Pwn20wn contest, and the proof-of-concept exploit developed by PureHacking for this threat demonstrate otherwise. That said, Mac OS X is still a drop in the bucket for PC market share and malware developers have their attention focused on the big pool, so there is little risk of this being exploited in the wild any time soon.

Is there a fix?Skype claims to have been aware of the issue even before PureHacking brought it to its attention, and has already developed a hotfix which has been available since April 14. Skype has not pushed the hotfix, though, because it is not aware of this flaw being exploited in the wild. Next week, Skype will push an updated version of Skype for Mac 5.x which resolves the problem, and includes a variety of other tweaks and fixes as well.

What should I do?If you are really concerned, get the hotfix from Skype and apply it now. If you prefer, though, you can probably just wait until next week when Skype .