A serious browser vulnerability, but whose?
Security researchers can't decide whether it's in IE or Firefox
A serious vulnerability that causes Internet Explorer to launch Firefox and execute a malicious payload is sparking debate about exactly who is responsible for the flaw.
The vulnerability, which was widely reported on security blogs, allows an attacker to remotely execute malicious code on a machine that is running IE but also has the Mozilla browser installed. By luring an IE user to a malevolently crafted site, the attacker can cause Firefox to execute the code without first vetting it for security.
The saying about success having many parents but failure being an orphan seems fitting here. Window Snyder, who heads security at Mozilla, wrote today that Mozilla developers will patch Firefox so it no longer accepts bad data from IE. But she stressed that only people browsing with the Microsoft browser were vulnerable to the attack.
"We recommend that people use Firefox and as always take care when browsing unknown websites," she wrote.
For its part, Microsoft representatives said company researchers have "investigated the claim of a vulnerability in Internet Explorer and found that this is not a vulnerability in a Microsoft product." Jesper Johansson, a former senior security strategist for Microsoft, similarly argues that "most definitely" the problem isn't caused by IE.
"Firefox fails to properly validate the parameters, and any fix will have to come from Mozilla, not Microsoft," he wrote in a blog entry.
A proof of concept exploit found here uses IE to hand off maliciously-scripted code to a Firefox handler known as "firefoxurl." Handlers, which also include strings such as "ftp" and "aim," are found in the address bar and in many cases can be used to get Firefox to carry out certain actions.
Roger Thompson, CTO of Exploit Prevention Labs, says Microsoft shares culpability because IE fails to properly validate the input before passing it along.
"I think it's an IE issue mostly, because if you access the exploit directly with Firefox, FF warns you that something bad is happening and advises you to not do it," he said in an instant message. ®
Is IE partly to blame?
I've just attempted a number of different ways of launching this exploit, but can't seem to get it to execute except from IE.
* Attempting to launch it by pasting the URL into FF shows a warning with the full URL. Accepting this warning just brings up another warning about "firefoxurl:test". Accepting this one just brings up another, etc, creating a new tab each time.
* Attempting to launch it via the ShellExecute API doesn't work. FF warns about "firefoxurl:test", not the entire URL.
* Launching the URL from IE (either via the link or pasting the URL into the address bar) causes the exploit to run.
It certainly seems that IE is partly to blame, because it does something different in how it executes these links. Perhaps MS should patch IE so that it uses standard mechanisms to launch these links, rather than whatever method it currently uses.
Windows - ROFL
Re-affirms my disbelief of people porting IE to Linux via WINE. How many slaps in the face like this do you need before you realise that no-means-no? I'm with Max - wait until this results in shots at winword.exe, cmd.exe, rundll32.exe, explorer.exe .. etc ad nausea .. you can almost sense the silent update coming ..
> BTW, is 'facetious' the only word that contains all five vowels in alphabetic order?
No, search via;