A new, unpatched flaw in that affects all versions of Firefox could let attackers surreptitiously run malicious code on users" PCs, a security researcher has warned.
The problem lies in the way Firefox handles Web links that are overly long and contain dashes, security researcher Tom Ferris said in an interview via instant messaging late Thursday.
The security vulnerability is a buffer overflow flaw that "allows for an attacker to remotely execute arbitrary code" on a vulnerable PC, Ferris said. An attacker could host a Web site containing the malicious code to exploit the flaw, he said. Though his proof of concept only crashes Firefox, Ferris claims he has been able to tweak it to run code.