Feeds

Tech titans meet in secret to plug SSL hole

Web authentication busted on Apache, IIS

Intelligent flash storage arrays

Researchers say they've uncovered a flaw in the secure sockets layer protocol that allows attackers to inject text into encrypted traffic passing between two endpoints.

The vulnerability in the transport layer security protocol allows man-in-the-middle attackers to surreptitiously introduce text at the beginning of an SSL session, said Marsh Ray, a security researcher who discovered the bug. A typical SSL transaction may be broken into multiple sessions, providing the attacker ample opportunity to sneak password resets and other commands into communications believed to be cryptographically authenticated.

Practical attacks have been demonstrated against both the Apache and Microsoft IIS webservers communicating with a variety of client applications. A consortium of some of the world's biggest technology companies have been meeting since late September to hash out a new industry standard that will fix the flaw. A draft is expected to be submitted on Thursday to the Internet Engineering Task Force.

"A core security guarantee made by TLS is violated as a result of this problem," said Steve Dispensa, CTO of PhoneFactor, a provider of two-factor authentication services, the company where Ray works. "It's going to take a while for the protocol changes necessary to be rolled out, because every browser and every server in the world is going to have to be patched."

Ray and Dispensa were quick to note that the vulnerability would most likely have to be exploited in concert with some other security weakness, say a flaw in a home router or the recent DNS bugs discovered by researcher Dan Kaminsky. And even then, an attacker would be unable to read encrypted data that flowed between a server and a client.

Indeed, Moxie Marlinspike a security researcher who has repeatedly exposed serious shortcomings in SSL, said the attacks were hard to pull off in the real world, in large part because they appeared to target a rarely used technology known as client certificate authentication.

"It's clever, but to my knowledge the common cases in which the majority of people use SSL (webmail, online banking, etc.) are currently unaffected," he wrote in an email. "I haven't found these attacks to be very useful in practice."

But Ray and Dispensa said there are attacks that don't rely at all on client authenticated certificates. They maintained that the ability of an attacker to inject plaintext of his choice into an authenticated data stream represented a major threat. And they said the attack has special implications for smartcards and other technologies that rely on client authenticated certificates.

"There is consensus among the biggest vendors in the world that it's a big problem," Dispensa said.

Already, developers from OpenSSL and GNU TLS have developed patches and are in the process of testing them. Other providers of hardware and software that implement SSL are in various stages of patching as well. Dispensa and Ray presented their findings under a non-disclosure agreement to a large number of company representatives on September 29 in Mountain View, California, at a company they declined to name.

The parties had planned to continue working on a fix in secret throughout the rest of the year. Coincidentally, a separate researcher recently documented the basics of the protocol defect and made some of the findings public, prompting Ray to disclose his research. The flaw has existed in TLS since the specification was published in the mid 1990s.

The vulnerability stems from the ability for either party in an SSL transaction to renegotiate the session, usually so one or the other can refresh its cryptographic keys. Because HTTP lacks a way to direct the client to resubmit the request within a newly authenticated channel, the server must apply the authentication retroactively. ®

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

10 ways wire data helps conquer IT complexity
IT teams can automatically detect problems across the IT environment, spot data theft, select unique pieces of transaction payloads to send to a data source, and more.
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.
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.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.