Defence Driven by Understanding the Attacker’s M... » LONDON, UK: MWR InfoSecurity, has confirmed details of its latest service – Countercept, a complete ... Cheshire West & Chester Council use Becrypt tVol... » London, UK: Becrypt has announced that Cheshire West & Chester Council have chosen tVolution Mini to... Secunia and Blue Cube Security announce new partne... » Secunia has signed a Value Added Reseller agreement with specialist reseller Blue Cube Security. The... Ipswitch Network and Server Performance Monitoring... » Denmark: Ipswitch Inc. has announced that its WhatsUp Gold® network and server performance monitorin... LANDESK and WinMagic partner to provide enterpri... » LONDON: LANDESK has announced it has certified and is now reselling WinMagic's suite of SecureDoc pr... How Muhammadu Buhari is camouflaging as the silent... » In the 21st century Nigeria, naivety still pervades its politics: It is shocking and embarrassing t... Enterprises signing up for more than one new cl... » LONDON: European enterprises are adding new cloud services at a rapid rate, finds a new report from ... Police to hold major exercise in central London th... » A major exercise to test the emergency services and Government response to a terrorist attack will b... Most major financial hacks completely covered u... » London, UK: Despite devastating cyber attacks being reported daily in the media, a new survey from L... What Makes Close Protection Unique? » TB Close Protection Operatives have to deal with a wide range of threats that many others who uti...

CLICK HERE TO

Advertise with Vigilance

Got News?

Got news for Vigilance?

Have you got news/articles for us? We welcome news stories and articles from security experts, intelligence analysts, industry players, security correspondents in the main stream media and our numerous readers across the globe.

READ MORE

Subscribe to Vigilance Weekly

Information Security Header

Many recognise that the internet is an insecure place to be, but sometimes the browser itself can heighten this likelihood. In his latest blog post, Jonathan Kuskos WhiteHat's A-Team Application Security Engineer, warns to the danger of an unconventional attack in Firefox (versions 21 and below) - Cross Site Request Forgery.

In his commentary, Jonathan:

Explains ‘Cross Site Request Forgery’

Explains ‘verb tampering’

Uses examples to show how this attack works

Warns that, while Firefox 22 has been patched, previous versions remain vulnerable - highlighting the issue that users should update browsers to remain secure

 

It appears that an unconventional method of Cross Site Request Forgery may be made exploitable by using Firefox versions 21 and below. The exploit requires that the target application be first vulnerable to HEAD request verb tampering, which is where a HEAD verb(also commonly known as 'method') is supplied in place of a GET or POST, and is successfully processed by the application. Once this is found, an XMLHttpRequest(commonly abbreviated to 'XHR') request can be sent from an off-domain location with the .open() method invoked and HEAD supplied as the verb.

The XMLHttpRequest Living Standard specifications can be found here and defines how XHR objects should be used. Although there are many rules, steps 3 and 4 of the .send() method serve particular interest to this implementation error:

.send(data);

3) If the request method is GET or HEAD, set data to null.

4) If data is null, do not include a request entity body and go to the next step.

Consider the following very basic and elementary Proof of Concept:

If you monitor your traffic or catch this in an intercepting proxy, you will see a request being made to https://www.whitehatsec.com with post data "foo=bar", even though the request verb is HEAD. According to step 3 above, 'data' should have been set to 'NULL'. This behavior seems to only occur in Firefox; The latest versions(as of this writing) of Internet Explorer, Chrome, Safari, and Opera are all successfully practicing proper .send() implementation.

I notified Mozilla of this behavior and a patch has been implemented into the v22 build. Until then Firefox 21 and those that refuse to ever update their browser will remain susceptible targets. It requires a bit of a "perfect storm" scenario, but nonetheless the second most widely used browser in the world should never ineptly contribute to CSRF.