Zero-day security flaw leaves Firefox wide open
Uri: Russian thug or hacker's paradise?
Security researchers have disclosed a zero-day vulnerability in the latest version of Firefox that gives miscreants complete control of Windows-based computers when the Mozilla browser visits a booby-trapped website.
The vulnerability resides in the way Firefox handles uniform resource identifiers, the protocols that allow the browser to access software and other resources located on a PC. The browser fails to properly vet at least five different URIs, a flaw that could allow an attacker to install malware on a PC simply by convincing a victim to click on a doctored link.
Over the past few months, URIs have emerged as one of the weaker links in the online security chain. Last week, Mozilla patched Firefox to fix another critical flaw related to URI handling. Internet Explorer and the Trillian instant messaging program have also fallen victim to the often overlooked protocol.
The problem is the result of the wealth of poorly documented URIs that countless third-party applications add to the Windows registry. Browsers are frequently ill-prepared to screen URI handlers for security exploits, and even when they are, related applications are often unable to parse the restrictions - or are prone to their own security vulnerabilities, said Billy Rios, one of the researchers who discovered the flaw.
With each registered URI, a PC's attack surface increases.
"It's a perfect storm where the browsers aren't really doing their job in terms of sanitizing the URIs and applications that are registering these URIs aren't really able to properly handle the parameters that are being passed to it from the browser," Rios told El Reg.
Mozilla's security team is aware of the flaw, which was reported on the Billy (BK) Rios blog, and is working on a patch, a spokesman for the open-source organization said.
An episode that played out over the past few weeks demonstrates just how difficult it is to tackle the problem. Last week, Mozilla patched a hole in Firefox that allowed the browser to accept malicious URIs that were passed from IE. Microsoft security officials argued that validation is the job of the application receiving the input and said flaw rested solely in Firefox.
Window Snyder, Mozilla's chief security officer, disagreed, arguing that IE should screen the URI before passing it along and warned that other Windows applications could also be vulnerable.
To further complicate matters, Snyder later acknowledged that Firefox could indeed be used to pass off a bad URI, proving there is plenty of culpability when it comes to the way browsers and other applications work with the protocol.
The latest Firefox flaw is particularly serious because it can be exposed anywhere a person is vulnerable to a cross-site scripting attack. That includes documents or emails containing malicious links or, potentially, forums containing hidden scripts. The vulnerability is also present in Netscape Navigator 9, and the Mozilla browser.
As is often the case with Firefox vulnerabilities, a browser extension called NoScript can mitigate the exploit. Indeed, we had to disable it in order to get proof of concept links (at the bottom of this page) to work. ®
Re: None of then recieved a heroes welcome.
In response to the person above who unfortunately had to withhold their name, it's all very simple. If it's secure, it's secure. If Fire Fox 1.00 was as safe as they claimed then it would be perfectly safe to use in 10 years time. It may lack new features and there may be holes in the underlying operating system that are patched along the way, but there shouldn't be holes in the browser itself that render it unsafe. I say this only because of the great hype generated by Mozzila about security - live by the sword, die by the sword, and all that.
Fire Fox 1.00 is, of course, already very unsafe and it was only out a couple of years ago. And Opera and Safari have much better track records in security than Fire Fox and IE, it's a statistical fact (just browse the stats on the Secunia website) that can only be overcome by the religious fervour of fanbois. Another fact is that Mozzila made fun of the 'patch' system IE uses and released complete versions until of course they rocketed through 1.0.xx releases due to regular security holes being discovered. Then they switched to the patch system which they said was 'an improvement', since which the number of security holes and patches continues to climb through double figures.
But, them's all just browsers and it's the weekend, so chill. Though understand that when someone stands up and claims to be the worlds most intelegent person and then starts to get the pub quiz questions wrong, they're going to get more stick than those who just did their best...
Won't get fooled again - really!
You sound like an idiot who has no clue about security or worse a Microsoft shrill.
Proper security is a evolving _process_ based on many layers e.g. NoScript is a security layer which all Firefox users should have, restricted accounts, anti-virus, firewalls and NAT routers are other layers.
Don't expect applications to be 100% secure on their own, especially complex, interactive, pluggable software like browsers, which can be quite tough to secure, especially fatally insecure crud like IE!
Mozilla and the authors of security plugins like NoScript and Adblock are doing a far better job overall than Opera and Microsoft, and tend to fix issues very quickly!
A lot of these new security issues are being aggressively searched for by very smart security professionals, to make honest money and reputation, better they find them and force a fix before criminals find them and wreck your machine!
Firefox patches vs. Internet Explorer patches
So we'll probably see a patch for this vuln by the end of today. When will we see a patch for the next IE vuln? In a month or so?