Risk
7/8/2013
11:48 AM
50%
50%

Encrypted IM Tool Vulnerable To Eavesdropping

Bugs in instant messaging encryption tool Cryptocat left users' group chats vulnerable to eavesdropping for over a year, says security researcher.

The Syrian Electronic Army: 9 Things We Know
(click image for larger view)
The Syrian Electronic Army: 9 Things We Know
Cryptocat, a free tool designed to encrypt online chats, has been updated to fix errors that would have allowed an attacker to eavesdrop on chats. The vulnerability resulted from developers using below-minimum public key sizes or iterations. As a result, anyone who used a vulnerable version of Cryptocat to hold a group conversation, or who communicated with anyone using the software, could have had their communications easily intercepted.

That warning was sounded by security researcher Steve Thomas, who detailed the errors in a blog post. "If you used group chat in Cryptocat from Oct. 17th, 2011 to June 15th, 2013, assume your messages were compromised," he said. "Also if you or the person you are talking to has a version from that time span, then assume your messages are being compromised."

Thomas built a tool he calls DecryptoCat, which "cracks the ECC public keys generated by Cryptocat versions 1.1.147 through 2.0.41" in about a day, he said. Using the information generated by the tool, it would then take just a few minutes to crack any vulnerable Cryptocat key. Based on the coding errors he found, Thomas had harsh words for the chat tool's developers, who he labeled as being "incompetent." "I feel bad about calling them incompetent, but it is true. If you mess up in all the places I cared to check ... that's incompetence," he said.

[ Need an encryption how-to? Read 5 Rules For (Almost) Painless Encryption. ]

In response, Cryptocat issued an apology, and said that the bug detailed by Thomas -- which they claimed left users' communications vulnerable for only seven months -- was rapidly fixed. "The vulnerability was quickly resolved and an update was pushed," said the Cryptocat development blog post. "We sincerely thank Steve for his invaluable effort."

The developers emphasized that it's impossible to keep software entirely free from bugs. "Bad bugs happen all the time in all projects," they said. "Cryptocat is not any different from any of the other notable privacy, encryption and security projects, in which vulnerabilities get pointed out on a regular basis and are fixed. Bugs will continue to happen in Cryptocat, and they will continue to happen in other projects as well. This is how open source security works."

Previous
1 of 2
Next
Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Flash Poll
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-9651
Published: 2015-08-28
Buffer overflow in CHICKEN 4.9.0.x before 4.9.0.2, 4.9.x before 4.9.1, and before 5.0 allows attackers to have unspecified impact via a positive START argument to the "substring-index[-ci] procedures."

CVE-2015-1171
Published: 2015-08-28
Stack-based buffer overflow in GSM SIM Utility (aka SIM Card Editor) 6.6 allows remote attackers to execute arbitrary code via a long entry in a .sms file.

CVE-2015-2987
Published: 2015-08-28
Type74 ED before 4.0 misuses 128-bit ECB encryption for small files, which makes it easier for attackers to obtain plaintext data via differential cryptanalysis of a file with an original length smaller than 128 bits.

CVE-2015-6266
Published: 2015-08-28
The guest portal in Cisco Identity Services Engine (ISE) 3300 1.2(0.899) does not restrict access to uploaded HTML documents, which allows remote attackers to obtain sensitive information from customized documents via a direct request, aka Bug ID CSCuo78045.

CVE-2015-6267
Published: 2015-08-28
Cisco IOS XE before 2.2.3 on ASR 1000 devices allows remote attackers to cause a denial of service (Embedded Services Processor crash) via a crafted L2TP packet, aka Bug IDs CSCsw95722 and CSCsw95496.

Dark Reading Radio
Archived Dark Reading Radio
Another Black Hat is in the books and Dark Reading was there. Join the editors as they share their top stories, biggest lessons, and best conversations from the premier security conference.