Secure messaging project, Cryptocat, apologizes over bug

The open-source IM project warned that encrypted group chats may have been easier to crack for seven months

The founder of an eavesdropping-resistant instant messaging application called Cryptocat has apologized over a now-fixed bug that made some types of messages more vulnerable to snooping.

Cryptocat, which runs inside a web browser, is an open-source application intended to provide users with a high degree of security by using encryption to scramble messages. But Cryptocat warns that users should still be very cautious with communications and not to trust their life with the application.

The vulnerability, found by Steve Thomas, affected group chats and not private conversations, said Nadim Kobeissi, in an interview from Germany Friday. The encryption keys used to encode those conversations were too short, which in theory made it easier for an attacker to decrypt and read conversations.

The error was the result of an oversight spotted by Thomas, Kobeissi said. The encrypted conversations were still carried over SSL (Secure Sockets Layers), another overlay of encryption. But if an attacker broke the SSL encryption and had the underlying encrypted chats, "it would be significantly easier to crack" using brute-force techniques, he said.

The bug was fixed in Cryptocat versions 2.0 and up about a month ago after Thomas notified the project. The vulnerability persisted for about seven months between September 2012 and April.

Although Cryptocat noted the patch in its changelog, Kobeissi wrote a detailed blog post on Thursday explaining the issue after Thomas published a sharp critique.

"This is a really difficult situation," Kobeissi said. "I am not a person who will gloss over this kind of bug for absolutely no reason just to maintain the image of the project."

The bug was completely unacceptable, but it is common for errors to be revealed in open-source projects, he said. Kobeissi said he gave Thomas a US$250 reward out of his own pocket even though Cryptocat has no formal bug bounty program.

"I wanted to be on the record that he was paid for his effort," Kobeissi said.

Cryptocat has seen surging interest since the U.S. National Security Agency's surveillance program was detailed by whistleblower Edward Snowden. Kobeissi said Cryptocat saw 65,000 new users in just a month since the revelations were published.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags instant messagingInternet-based applications and servicesCryptocat

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jeremy Kirk

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?