Firefox and Internet Explorer users beware: There are serious, unpatched flaws in both browsers that could allow the manipulation of authentication cookies and the hijacking of files from your Windows machine. Details on both vulnerabilities have already been posted to the Full Disclosure mailing list by Polish researcher Michal Zalewski. SecurityFocus provides coverage of the issue, which dates back to 2006. According to Zalewski, a well-known hacker credited with several major flaw discoveries, there are two very different issues affecting Firefox and IE 7.