Twitter ‘onMouseOver’ security flaw widely exploited

The Twitter website is being widely exploited by users who have stumbled across a flaw which allows messages to pop-up and third-party websites to open in your browser just by moving your mouse over a link. In a worrying development, messages are also spreading virally exploiting the cross-site-scripting (XSS) vulnerability without the consent of users.

Thousands of Twitter accounts have posted messages exploiting the flaw. Victims include Sarah Brown, wife of the former British Prime Minister.

It appears that in Sarah Brown’s case her Twitter page has been messed with in an attempt to redirect visitors to a hardcore porn site based in Japan. That’s obviously bad news for her followers – over one million of them.

To Mrs Brown’s credit, she has posted a warning on her Twitter page:

don’t touch the earlier tweet – this twitter feed has something very odd going on ! Sarah

Here’s an example of a Twitter profile which is using the exploit to pop-up a message…

Read more in my article on the Naked Security website.

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Graham Cluley •   @gcluley

Graham Cluley is a veteran of the anti-virus industry having worked for a number of security companies since the early 1990s when he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows. Now an independent security analyst, he regularly makes media appearances and is an international public speaker on the topic of computer security, hackers, and online privacy. Follow him on Twitter at @gcluley, on Mastodon at @[email protected], or drop him an email.