Feeds

New RADIUS vulns exposed

No rest for the wicked

  • alert
  • submit to reddit

3 Big data security analytics techniques

Numerous holes in the ubiquitous RADIUS (remote authentication dial-in user service) protocol can be exploited with results including denial of service and running arbitrary code on the target device, a Russian security researcher has demonstrated. The risk of the DoS attack is considerably greater, and can be achieved two ways.

First up, according to a bulletin by '3APA3A', during authentication in several implementations a digest is created consisting of an initial packet, a message authenticator and a shared secret concatenated and calculated as an MD5 hash. Unfortunately, the process doesn't check for adequate space in the target buffer. Thus a shared secret can be used to overload the buffer, and cause a denial of service.

If the shared secret were accurately guessed, an attacker could get privileges on the target RADIUS client or server. While this is far from a trivial exercise, we note that according to researcher Joshua Hill, "most client and server implementations only allow shared secrets to be input as ASCII strings. There are only 94 different ASCII characters that can be entered from a standard US style keyboard (out of the 256 possible). Many implementations also restrict the total length of the shared secret to 16 characters or less. Both of these restrictions artificially reduce the size of the keyspace that an attacker must search in order to guess the shared secret."

Next up, still following the 3APA3A bulletin, we have improper validation of a vendor-specific attribute. Vendor-specific and user-specific attributes can be passed to the client. If the vendor-specific header contains less than two bytes, it will be calculated as a negative number and a denial of service will result. It is not necessary to know the shared secret to abuse this flaw.

RADIUS is used widely by ISPs and NSPs for remote user authentication, so these issues are likely to affect a large number of admins and a vast heap of equipment and software. It's ubiquitous chiefly because it's embedded in numerous devices such as routers and switches.

3APA3A has a simple tool for testing RADIUS vulnerabilities available here.

CERT has a bulletin listing all equipment and software presently known to be vulnerable, along with links to the vendors, posted here. ®

SANS - Survey on application security programs

More from The Register

next story
This time it's 'Personal': new Office 365 sub covers just two devices
Redmond also brings Office into Google's back yard
Kingston DataTraveler MicroDuo: Turn your phone into a 72GB beast
USB-usiness in the front, micro-USB party in the back
Dropbox defends fantastically badly timed Condoleezza Rice appointment
'Nothing is going to change with Dr. Rice's appointment,' file sharer promises
BOFH: Oh DO tell us what you think. *CLICK*
$%%&amp Oh dear, we've been cut *CLICK* Well hello *CLICK* You're breaking up...
Just what could be inside Dropbox's new 'Home For Life'?
Biz apps, messaging, photos, email, more storage – sorry, did you think there would be cake?
IT bods: How long does it take YOU to train up on new tech?
I'll leave my arrays to do the hard work, if you don't mind
Amazon reveals its Google-killing 'R3' server instances
A mega-memory instance that never forgets
Cisco reps flog Whiptail's Invicta arrays against EMC and Pure
Storage reseller report reveals who's selling what
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.