Feeds

A serious browser vulnerability, but whose?

Security researchers can't decide whether it's in IE or Firefox

Internet Security Threat Report 2014

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. ®

Remote control for virtualized desktops

More from The Register

next story
UK smart meters arrive in 2020. Hackers have ALREADY found a flaw
Energy summit bods warned of free energy bonanza
DRUPAL-OPCALYPSE! Devs say best assume your CMS is owned
SQLi hole was hit hard, fast, and before most admins knew it needed patching
Knock Knock tool makes a joke of Mac AV
Yes, we know Macs 'don't get viruses', but when they do this code'll spot 'em
Feds seek potential 'second Snowden' gov doc leaker – report
Hang on, Ed wasn't here when we compiled THIS document
Mozilla releases geolocating WiFi sniffer for Android
As if the civilians who never change access point passwords will ever opt out of this one
Why weasel words might not work for Whisper
CEO suspends editor but privacy questions remain
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
Internet Security Threat Report 2014
An overview and analysis of the year in global threat activity: identify, analyze, and provide commentary on emerging trends in the dynamic threat landscape.