Feeds

Researchers release point-and-click website exploitation tool

'Tons' of vulnerable sites

Intelligent flash storage arrays

Researchers have released software that exposes private information and executes arbitrary code on sensitive websites by exploiting weaknesses in a widely used web development technology.

Short for Padding Oracle Exploitation Tool, Poet is able to decrypt secret data encrypted by the JavaServer Faces web development framework without knowing the secret key. Attackers can use the technique to access private customer data on websites operated by banks, e-commerce companies and other businesses, according to a paper (PDF) released in February by researchers Juliano Rizzo and Thai Duong. In some cases, the exploit can be used to run malicious software on the underlying server.

Released Monday, Poet exploits a well-known vulnerability in the way many websites encrypt text stored in cookies, hidden HTML fields and request parameters. The text is designed to help servers keep track of purchases, user preferences and other settings while at the same time ensuring account credentials and other sensitive data can't be intercepted. By modifying the encrypted information and sending it back to the server, the attackers can recover the plaintext for small chunks of the data, allowing them to access passwords and restricted parts of a webserver.

The fatal flaw making exploitation possible is the failure of JavaServer Faces to implement AES/DES encryption algorithms correctly. The scheme provides no way to sign the ciphertext or authenticate the block cipher mode.

“The tool exploits a very common mistake -- using encryption alone instead of encryption + authentication/integrity protection," Rizzo told The Register. "You can get information about the plaintext from the server reaction.”

The attack can be used by crawling a target website for strings of encrypted strings and then modifying the last block of the ciphertext by a random value and sending it back to the server. The resulting error messages are then used to decipher the text, allowing attackers to bypass CAPTCHAs, view customer account numbers and even create webpages that will execute malicious software on the underlying server. Attackers can also use the technique to map all ciphertexts to corresponding plaintexts, a feat that breaks a website's underlying cryptosystem.

Attackers can also use Google to find websites that are vulnerable to attack. Queries such as “Given final block not properly padded” and “javax.crypto.BadPaddingException” reveal “tons” of exposed web applications, the researchers said.

The researchers tested the attack in JavaServer Faces implemented into the Apache webserver, as well as Sun's Mojarra. They said many other implementations are also likely to be vulnerable.

Poet runs on Windows, Mac OS X and Linux and is available here . Video showing the exploit code in action is here. ®

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
Regin: The super-spyware the security industry has been silent about
NSA fingered as likely source of complex malware family
Why did it take antivirus giants YEARS to drill into super-scary Regin? Symantec responds...
FYI this isn't just going to target Windows, Linux and OS X fans
Privacy bods offer GOV SPY VICTIMS a FREE SPYWARE SNIFFER
Looks for gov malware that evades most antivirus
Home Office: Fancy flogging us some SECRET SPY GEAR?
If you do, tell NOBODY what it's for or how it works
HACKERS can DELETE SURVEILLANCE DVRS remotely – report
Hikvision devices wide open to hacking, claim securobods
'Regin': The 'New Stuxnet' spook-grade SOFTWARE WEAPON described
'A degree of technical competence rarely seen'
Syrian Electronic Army in news site 'hack' POP-UP MAYHEM
Gigya redirect exploit blamed for pop-rageous ploy
Astro-boffins start opening universe simulation data
Got a supercomputer? Want to simulate a universe? Here you go
prev story

Whitepapers

Driving business with continuous operational intelligence
Introducing an innovative approach offered by ExtraHop for producing continuous operational intelligence.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
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?
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.