In terms of cybersecurity, the risk is now everywhere including on low layers like processors. After the discovery of Spectre and Meltdown, the same team of researchers has highlighted another vulnerability this time on Cascade Lake Intel chips used by Xeon series running on servers and the Core series for the general public.

After Spectre and Meltdown, another vulnerability affects Intel processors. A variant of the Zombieland attack would target chips under micro-architecture Cascade Lake.


The latter was highlighted last May by researchers at the Vrije Universitet Amsterdam. They named their Rogue In-Flight Data Load or RIDL side channel attack technique. The vulnerability lies within the TAA (Transactional (TSX) Asynchronous Abort), that is, how the chip attempts to anticipate the impacts of future commands.

This technique known as speculative execution, accelerates the operation of chips. But a faulty design gives hackers the ability to extract potentially sensitive data. This demonstrate again that it's very hard to find the extract balance between performance and safety!


To appreciate the ZombieLoad CVE-2018-12130 vulnerability, you first have to look back to earlier speculative execution side-channel attacks. Thomas Brewster wrote a good primer on these vulnerabilities in this Forbes article from May 2018.

A variant of Zombieload flaw hits Intel's Newest Cascade Lake Chips

While programs normally only see their own data, a malicious program can exploit internal CPU buffers to get hold of secrets currently processed by other running programs. These secrets can be user-level secrets, such as browser history, website content, user keys, and passwords, or system-level secrets, such as disk encryption keys. If you want to learn more about the new variant, we welcome you to read the updated version of our publication or checkout Intel's One Pager, Deep Dive, and Security Advisory Disclosure.


Intel had at that time corrected the flaw, but according to researchers the patch is incomplete. "The Cascade Lake chip design changes were not enough to protect against side channel attacks." Sparked, the Santa Clara firm announced the availability of a fix for these recent chips by disabling TSX.

It recognizes however that this patch does not guarantee absolute protection and that other attacks via side channel remains possible. Intel nevertheless wants to reassure because it has not observed "active exploits based on these vulnerabilities".