Two new vulnerabilities in Internet Explorer 6.0 were unveiled by a security firm Wednesday that hackers could exploit to bypass security features even in Microsoft's most secure OS, Windows XP SP2.

According to Danish security company Secunia, the "highly critical" vulnerabilities stem from a flaw in IE's drag-and-drop feature and in the browser's security zone. Hackers could exploit these bugs by enticing users to malicious Web sites, where specially crafted files--including image and help files--could compromise the PC, leaving it open to attack or hijack.

Both bugs can be exploited to circumvent Windows XP SP2's Local Computer zone lockdown security feature, said Secunia.

"This has been confirmed on a fully patched system with Internet Explorer 6.0 and Microsoft Windows XP SP2," wrote Secunia in its online alert.

As is its usual practice when it touts critical problems in IE, Secunia recommended that users either disable Active Scripting in the browser, or switch to an alternate, such as Mozilla's Firefox.