Integer overflow in Windows Explorer in Microsoft Windows XP SP1 might allow user-assisted remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a large width dimension in a crafted BMP image, as demonstrated by w4intof.bmp.
http://www.securityfocus.com/bid/23321
http://www.securityfocus.com/archive/1/464726/100/0/threaded