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 Follow me on Twitter: @jeremy_kirk

Join the CSO newsletter!

Error: Please check your email address.

Tags instant messagingInternet-based applications and servicessecurityCryptocatencryption

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Jeremy Kirk

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

More videos

Blog Posts

Market Place