Java flaws bust Navigator security

A bug in Navigator allows anyone to read a PC's local files over the Internet.

The startling hole affects every Navigator since version 4 on all operating systems. Dubbed Brown Orifice by the person who posted a program to exploit the hole, the bug's potential damage has already been over-hyped by the press but as one expert told The Reg: "It's still pretty bad."

The problem results from two complementary errors. First of all, flaws in Netscape's code and Sun's Java allow a network socket to be kept open and accept connections on that socket respectively. Secondly, a flaw in Netscape's Java allows an applet to read any local files by simply tapping in a URL in the form "file://".

The hole cannot be used to run or change any of the files, as has been falsely claimed by the IT press (so no viruses etc), but remains extremely damaging as external viewers will be able to pore over whatever exists on the hard drive. It's not hard to see that with a little imagination, extensive damage could be done to a company and its network.

The implications are massive and as yet Netscape/AOL has failed to come up with a patch. Over a thousand people are known to have downloaded the exploitative applet so far and that's likely to be just the tip of the iceberg. It's not known whether the problem has been written out of version 6 of the browser, currently available in preview form. It seems unlikely though.

Focus' technical information on the problem can be found here.

Jack Clark of Network Associates hadn't had time to work on the flaw but wanted to stress that people need to start thinking differently about security. "People have to realise they should update all applications - it's not just Microsoft that suffers from security problems. Companies need to keep an eye on and employ fixes and updates," he told us. ®