Back in early January I wrote an article on the security of public Wi-Fi networks, which discussed and demonstrated how unsecure public Wi-Fis are.

From it, we asked website owners move onto SSL/TSL protocols.

As of yesterday this is now even more important as the major Wi-Fi security protocol, WPA2 has been found to have a severe flaw which allows hackers both to eavesdrop and inject content.

This means they can now change the content that reaches the user.

The big worry is that this is not a small issue as majority of the UK (and the world) runs on WPA2.

Due to the nature of this issue, we are unlikely to see this to be patched for many years (if at all), which essentially means that the majority of the country now runs on unsecure public Wi-Fi.

The proof-of-concept exploit is called KRACK, short for Key Reinstallation Attacks. This issue has been kept highly confidential for weeks until the coordinated disclosure till today. US Cert recently distributed the following on this issue:

US-CERT has become aware of several key management vulnerabilities in the 4-way handshake of the Wi-Fi Protected Access II (WPA2) security protocol. The impact of exploiting these vulnerabilities includes decryption, packet replay, TCP connection hijacking, HTTP content injection, and others. Note that as protocol-level issues, most or all correct implementations of the standard will be affected. The CERT/CC and the reporting researcher KU Leuven, will be publicly disclosing these vulnerabilities on 16 October 2017.

According to the researcher who has done the brief, this vulnerability works by exploiting the third step of the fourway handshake that is used by the protocol. During the third step the key is re-sent multiple times, and if it is altered in a specific way, this completely undermines the encryption. The CVE numbers that are going to be published can be found on twitter.

More information on the issue will be published on KrackAttacks site.

Do you trust public Wi-Fi?