Feeds

Crypto hash boffins trip on buffer overflow

Corvair of computer languages strikes again

3 Big data security analytics techniques

Two of the programs submitted in the first round of a competition to find the next cryptographic hash standard contain buffer overflow errors that could make them prone to crashes and security problems.

The discovery, by researchers at Fortify Software, just goes to show that even the world's most foremost security geeks can slip up when implementing their latest and greatest creations. In one case, a team lead by Massachusetts Institute of Technology professor Ronald Rivest - the R in the RSA cryptography algorithm - submitted a reference implementation that contained three buffer overflows. A second entry, dubbed Blender and submitted by Colin Bradbury, contained one.

Like all the contest submissions, the buggy reference implementations were written in C, often considered the Corvair of computer languages because of its susceptibility to critical security bugs.

"This just emphasizes what we already knew about C," Fortify researchers wrote. Even the most careful, security conscious developer messes up memory management."

The implementation submitted by Rivest's team suffered from a hashval field with a buffer that is read or written using different bounds. It's unlikely the mistakes would result in problems when the program is built using the standard ANSI compiler, but other compilers could allow it to be exploited. The bug was fixed by doubling the size of the vulnerable buffer, Fortify said.

The buffer overflow in Blender was the result of a typo. A developer mistyped3 instead of 2 for an array access. It required very large input in order to be caught.

The submissions are part of the competition sponsored by the National Institute of Standards and Technology, which is seeking a replacement to the current hash standards such as MD4, MD5, and SHA-0. Over the past few years, a growing body of research has revealed those algorithms can be vulnerable to so-called "collisions," in which two separate data files generate the same digital signature.

Fortify's analysis has already been greeted by a chorus of critics who point out the errors in the submission lie with source-code implementations rather than the soundness of the underlying algorithm.

Fortify doesn't deny this, but it does argue that reference implementations have a very long shelf life and that this means their weaknesses are likely to be with us for a long time.

"Reference implementations don't disappear, they serve as a starting point for future implementations or are used directly," the company stated. "A bug in the RSA reference implementation was responsible for vulnerabilities in OpenSSL and to separate SSH implementations. They can also be used to design hardware implementations, using buffer sizes to decide how much silicon should be used." ®

3 Big data security analytics techniques

More from The Register

next story
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Putin tells Snowden: Russia conducts no US-style mass surveillance
Gov't is too broke for that, Russian prez says
Snowden-inspired crypto-email service Lavaboom launches
German service pays tribute to Lavabit
Mounties always get their man: Heartbleed 'hacker', 19, CUFFED
Canadian teen accused of raiding tax computers using OpenSSL bug
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
Arts and crafts store Michaels says 3 million credit cards exposed in breach
Meanwhile, Target investigators prepare for long process in nabbing hackers
prev story

Whitepapers

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.
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.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.