Those people using certain older versions of Mozilla's flagship browser are strongly recommended to upgrade after an exploit was published for an image-handling flaw
http://chkpt.zdnet.com/chkpt/ukzdfeed/http://news.zdnet.co.uk/0,39020330,39207714,00.htm
http://chkpt.zdnet.com/chkpt/ukzdfeed/http://news.zdnet.co.uk/0,39020330,39207714,00.htm