Apologies for my early reply

Actually the link mentioned in the post says this

"An integer overflow in the libpng library can lead to a heap-buffer overflow when decompressing certain PNG images. This leads to a crash, which may be potentially exploitable."

which may be potentially exploitable

that's what is mentioned in the post.

Also check this

http://blog.mozilla.com/security/2012/02/17/mozilla-releases...

Regarding mouse over ads, apologies for not providing a good reading experience. Since the original link is in blue and the ad is in green, I thought it was easily distinguishable. I will look after it.

Thanks for the comment :)