Mozilla security official Daniel Veditz stopped short of pointing the finger at the authorities, but underlined the perceived risks involved in attempts to sabotage online privacy. The exploit is capable of sending the user's IP and MAC address to an attacker-controlled server, and resembles 'network investigative techniques' previously used by law-enforcement agencies to unmask Tor users, leading some in the developer community to speculate that the new exploit was developed by the FBI or another government agency and was somehow leaked. Thus we strongly recommend that all users apply the update to their Tor Browser immediately.' 'Even though there is currently, to the best of our knowledge, no similar exploit for OS X or Linux users available, the underlying bug affects those platforms as well. The code execution flaw was reportedly already being exploited in the wild on Windows systems, but in an advisory published later on Wednesday, Tor officials warned that Mac users were vulnerable to the same hack. Mozilla said in a blog post that the vulnerability had been fixed in a just-released version of Firefox for mainstream users. Privacy tool Tor is based on the open-source Firefox browser developed by Mozilla, which received a copy of the previously unknown JavaScript-based attack code yesterday. Mozilla and Tor have published browser updates to patch a critical Firefox vulnerability used to deanonymize users (via ArsTechnica).

New firefox update