An alarming amount of the webs top HTTPS sites have exploitable TLS vulnerabilities, according to research.
TLS, which stands for Transport Layer Security, is a web browser defence which encrypts data between your browser and the web servers it communicates with to protect your travel plans, passwords and search history. This is symbolised by a green padlock at the start of a web browsers search bar.
However, a surprising number of encrypted websites still leave these connections exposed, according to research teams at Ca' Foscari University of Venice and Tu Wien in Austria.
The teams analysed the web's top 10,000 HTTPs sites, ranked by Amazon's Alexa analytics company, and found that 5.5% had potentially exploitable TLS vulnerabilities.
These issues were caused by a combination of issues in how each site implemented TLS encryption schemes and a failure to patch known bugs. But what is most troubling about these flaws is that they are small enough that the green padlock will still appear.
"We assume in the paper that the browser is up to date, but the things that we found are not spotted by the browser," says Riccardo Focardi, a network security and cryptography researcher at Ca' Foscari University of Venice. "These are things that are not fixed and are not even noticed. We wanted to identify these problems with sites' TLS that are not yet pointed out on the user side."
Focardi and his fellow researchers will present their full findings at the IEEE Symposium on Security and Privacy in May. They developed TLS analysis techniques and also used some from existing cryptographic literature to crawl and vet the top 10,000 sites for TLS issues.
The researchers discovered TLS vulnerabilities in 5,574 hosts and broke them down as 4,818 vulnerable to MITM, 733 to full decryption and 912 to partial decryption. MITM stands for 'man-in-the-middle' attack and where a victim's communications to another site are intercepted by a third party, someone in the middle.
The other two categories involve more deeply flawed encryption channels between browsers and web servers that enable hackers to decrypt all the traffic passing through them. The worst variations of these are the "tainted" channel that allows hackers to not only decrypt the traffic but also modify and or manipulate it.
