For anyone working in IT security, this week surely did not start well. Not one, but two major cryptography-related vulnerabilities have been disclosed, and each of them is at least as massive in scale and potential consequences as the notorious Heartbleed incident from 2014.
First, a Belgian researcher Mathy Vanhoef from the University of Leuven has published the details of several critical weaknesses discovered in WPA2 – the de-facto standard protocol used for securing modern Wi-Fi networks. By exploiting these weaknesses, an attacker can launch so-called key reinstallation attacks (hence the name KRACK, and we’ve discussed the importance of catchy names for vulnerabilities before) and eventually decrypt any sensitive data transmitted over a supposedly secured wireless channel.
As opposed to Heartbleed, however, the vulnerability is not found in a particular library or a product – it’s caused by an ambiguity in the definition of the WPA2 protocol itself, so any operating system or library that implements it correctly is still vulnerable. Thus, all desktop and mobile operating systems were affected by this attack, as well as numerous embedded and IoT devices with built-in Wi-Fi capabilities. Somewhat luckily, this protocol weakness can be fixed in a backwards-compatible manner, so we do not have to urgently switch to WPA3 (and by no means you should switch to WEP or any other even less secure connection method in your wireless network). However, there is no other way to mitigate the problem without patching each client device. Changing the Wi-Fi password, for example, won’t help.
Of course, quite a few vendors have already released updates (including Microsoft), but how long will it take for everyone to apply these? And what about huge numbers of legacy products which will never be patched? The only way to secure them properly is to disable Wi-Fi and basically repurpose them as expensive paperweights. For desktop and mobile users, using HTTPS-only websites or encrypted VPN tunnels for accessing sensitive resources is recommended, just like for any other untrusted network, wireless or not. In general, one should slowly get used to the notion of treating every network as untrusted, even their own home Wi-Fi.
The second vulnerability revealed just recently is of a different nature, but already classified as even more devastating by many experts. The ROCA (Return of the Coppersmith’s Attack) vulnerability is an implementation flaw discovered by an international team of British, Czech and Italian researchers in a cryptographic library used in security chips produced by Infineon Technology. This flaw essentially means that RSA encryption keys generated using these chips are not cryptographically strong and are much easier to crack.
In theory, this problem should not be as widespread as the KRACK vulnerability, but in reality, it affects numerous security products from such vendors as Microsoft, Google, HP or Lenovo and existing RSA keys dating as far back as 2012 can be vulnerable. Also, since public key cryptography is so widely used in IT – from network encryption to signing application code to digital signatures in eGovernment projects – this opens a broad range of potential exploits: spreading malware, preforming identity theft or bypassing Trusted Platform Modules to run malicious code in secure environments.
What can we do to minimize the damage of this vulnerability? Again, it’s first and foremost about checking for available security updates and applying them in timely manner. Secondly, all potentially affected keys must be replaced (nobody should be using 1024-bit RSA keys in 2017 anyway).
And, of course, we always have be ready for new announcements. The week has only just begun, after all!