Two hackers over the weekend disclosed an "unpatchable" security flaw in the Firefox browser, possibly giving out enough information for attackers to replicate the bug, according to a report.

Mischa Spiegelmock and Andrew Wbeelsoi made the presentation, called "Lovin the LOLs, LOL is my will", at the ToorCon hacker conference in San Diego on Saturday. They said Firefox's implementation of JavaScript is responsible for the flaw, which they called "a complete mess", according to a report from industry journal

The bug affects Firefox on Windows, Mac OS X and Linux, and means that attackers could compromise a system simply by adding particular JavaScript code to a Web site, the hackers said. The exploit causes a stack overflow error, according to the report.

Spiegelmock and Wbeelsoi said Firefox's implementation of JavaScript is "a complete mess" and would be "impossible to patch", according to the report. Mozilla acknowledged that the bug could be difficult to fix if it involves the JavaScript virtual machine.

The disclosure follows several days of security difficulties for Microsoft's Internet Explorer browser. Last week Microsoft issued an emergency patch for IE after attackers began exploiting an unpatched security flaw on thousands of websites. The bug was used to plant a wide variety of malicious programs on users' systems.

Last month Symantec published a report showing that Firefox had acknowledged more security holes than IE. However, Symantec said Mozilla typically is much more prompt at acknowledging holes when they're reported, and is capable of patching more quickly, because of its open source nature.