A group called Packet Storm has published a paper detailing how the true IP addresses of Tor users can be discovered by the party that controls their traffic's exit node. In case all of that was Greek to you, let's back up: Tor is system that anonymizes internet traffic by routing it through a network of Tor nodes. The aim is to make it impossible to know where traffic originated, and Tor has become popular lately among the privacy minded, especially with the debut of Torpark, a version of Firefox with Tor's anonymizing features built in. Unfortunately, Packet Storm's paper shows that if you control the last node in the chain, it's possible to determine the traffic's originating IP using a combination Flash and cookie attack. The paper's author recommends turning off Flash, ActiveX, Java, and JavaScript if you use Tor and don't want your IP sniffed out. Tor's developers have yet to make an official statement about the exploit.

[Via Netscape]