Fergie's Tech Blog

Hotmail users exposed to cookie snaffling exploit

John Leyden writes in The Register:

A cookie manipulation exploit that created a possible means for hackers to break into Hotmail accounts forced Microsoft into pulling a portion of its website last weekend.

The exploitable page - http://ilovemessenger.msn.com - has been updated to remove a cross site scripting flaw that was the subject of the exploit. But Alex de Vries, the Dutch security enthusiast who discovered the trick, warns that other portions of MSN's site are still vulnerable.

The exploit works in three stages. Hackers use security loopholes to inject hostile code onto MSN's web site. Hackers can then harvest Hotmail cookies from surfers redirected to this contaminated page by taking advantage of the use of Hotmail cookies across the MSN.com domain. Once hackers have a victim's cookie they can use tools to trick Hotmail into thinking they already logged on as this user.

posted by Fergie @ 6/08/2005 07:28:00 AM