Mozilla is working on patching its Firefox browser after a hacker posted details of a flaw that could let criminals run unauthorized software on a victim's machine.

"Mozilla ponies up a patch for yet another critical flaw in Firefox, the latest embarrassment in a lengthening list this month for the open-source browser."

Officials at Mozilla said they have released an update to fix a flaw in the recently released 2.0.0.10 version of their Firefox browser.

A noted security researcher disclosed four new zero-day vulnerabilities in Microsoft and Mozilla's browsers, including a critical flaw in Internet Explorer (IE) and a major bug in Firefox.

It is really important that your system have the least and absolutely necessary services running, especially if it’s a public server. Okay, one might be thinking that they’ve got their firewalls up and running, blocking all the unnecessary ports and why should you bother?

Sometimes you get the flaw fixed right the first time and sometimes you don't. For Mozilla, apparently they have not properly fixed at least two types of flaws which they previously claimed to have fixed.

Mozilla chief evangelist Mike Shaver says the latest Firefox information leakage bug warning is exaggerated.

In an interesting twist on browser-based security issues, security researchers said they have found a flaw in which Microsoft's Internet Explorer can cause Mozilla's Firefox to execute remote malicious code. Security firm Secunia released an advisory Tuesday, ranking the flaw as highly critical. The vulnerability is confirmed on Firefox 2.0.0.4 on a fully-patched version of Windows XP SP2.

Popular as Web-based applications are becoming, the fact remains that most of them are tightly tied to the browser. In order to run Google Docs, for instance, you have to access it through a browser like Firefox or IE7. Mozilla Labs is working on Prism, a project it says could make Web apps run with the same ease and efficiency on the desktop as those natively installed on one's hard drive.