Feeds

Firefox-based attack wreaks havoc on IRC users

World's first inter-protocol exploit, but not the last

SANS - Survey on application security programs

Underscoring a little-known web vulnerability, hackers are exploiting a weakness in the Mozilla Firefox browser to wreak havoc on Freenode and other networks that cater to users of internet relay chat.

Using a piece of javascript embedded into a web link, the hackers force users of the open-source browser to join IRC networks and flood channels with diatribes that include the same internet address. As IRC users with Firefox follow the link, their browsers are also forced to spam the channels, giving the attack a viral quality that has has caused major disruptions for almost a month.

"Huge numbers of users of the Freenode network ended up getting banned themselves because they would click the link and then they would join the network and flood the network," one of the hackers, who goes by the moniker Weev, told The Register. "We get this huge rollover effect."

He added: "We got the the people who run Freenode to actually k-line each other," a reference to the process of banning a user from an IRC server for spamming or other inappropriate actions.

The malicious javascript exploits a feature that allows Firefox to send data over a variety of ports that aren't related to web browsing. By relaying the scripts over port 6667, users who click on the link automatically connect to the IRC server and begin spewing a tirade of offensive text and links. The attack doesn't work with Internet Explorer or Apple Safari, but "might" work with other browsers, Weev said.

IRC networks such as Efnet and OFTC have managed to block the attacks, but at time of writing Freenode operators were still struggling to repel them. (Weev has more details here, but readers are warned the page isn't safe for work and contains highly offense language.)

"While we are doing what we can to mitigate the spam, we would ask that you take a careful look at any unusual sites or URLs you might visit in the near future to be sure you are not being tricked into visiting such a site," a note on Freenode's website read. Representatives of the network didn't respond to an email seeking comment.

Security researchers have long known that it's possible to abuse features designed to make browsers work seamlessly with other internet applications. Web security expert Robert "RSnake" Hansen calls the technique "interprotocol exploitation."

"It's the first time I've actually seen it used in the wild," he said. "We've been theorizing this attack was possible for some time. Browsers absolutely should not be able to connect to ports unrelated to HTTP."

Hansen said other internet technologies, such as the session initiation protocol for voice over IP, are also ripe for abuse.

Weev - the same hacker behind an exploit that removed sales rankings for hundreds of books that contained gay and lesbian themes - agreed that IRC was only the beginning.

"We've got excellent stuff being developed in the lab," he said. "We're going to leverage this for some really fun things in the future." ®

Combat fraud and increase customer satisfaction

More from The Register

next story
Parent gabfest Mumsnet hit by SSL bug: My heart bleeds, grins hacker
Natter-board tells middle-class Britain to purée its passwords
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Web data BLEEDOUT: Users to feel the pain as Heartbleed bug revealed
Vendors and ISPs have work to do updating firmware - if it's possible to fix this
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Snowden-inspired crypto-email service Lavaboom launches
German service pays tribute to Lavabit
One year on: diplomatic fail as Chinese APT gangs get back to work
Mandiant says past 12 months shows Beijing won't call off its hackers
Call of Duty 'fragged using OpenSSL's Heartbleed exploit'
So it begins ... or maybe not, says one analyst
prev story

Whitepapers

Designing a defence for mobile apps
In this whitepaper learn the various considerations for defending mobile applications; from the mobile application architecture itself to the myriad testing technologies needed to properly assess mobile applications risk.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.