Twitter

This particular exploitation case relies on the poor sanitization of the user’s input and offers an attacker a way to “rig” a normal hyperlink with a JavaScript OnMouse event. This type of event does not require the user to click on the tweeted link; instead it is triggered when the user hovers the mouse cursor over the specially crafted link.

As of the moment of writing, Twitter was flooded by more than 2,000 messages experimenting with the flaw, ranging from “innocent” JavaScript alerts to sophisticated XSS attacks trying to steal cookies from the victims’ browsers.

Twitter has removed most of the tweets containing the vulnerability, but they are still cached in search engines.

Although Twitter have been notified and fixed the bug, one of the malicious links has been used to force each of its viewers to retweet a message that promised an alleged guide against the zero-day vulnerability.

This appears to be the original Tweet that has been retweeted by some victims

However, users that have accessed the link have been redirected to a website asking them to fill in surveys in order to allow access to the “guide”.