Got Firefox and Internet Explorer? Start worrying...

Reports are coming in that Firefox 2.0.0.4 users who also have a copy of Internet Explorer on their machines are at risk of a system hack that can - in theory at least - allow a hacker to take over control of their PC.

Mozilla is reported to be sufficiently worried that it is working on a fix, which should be available by the end of the month.

According to security wire reports, the flaw centres around the `firefoxurl://' URI handler, which allows Firefox to call on other Web resources.

Some security researchers have alleged that the URI is open to malicious code injection which could leave users at risk.

The problem is caused, apparently, because, when Firefox2 is installed, it registers the `firefoxurl' URI in the Windows registry which allows HTML rendering applications - like Internet Explorer - to spawn and execute Firefox.

What's interesting about this security problem is that the Firefox forums blame the issue on Internet Explorer - and - as you might expect - the Microsoft forums blame the problem on Firefox!

Still, at least Mozilla is on to the problem...