A new speculative vulnerability called ZombieLoad 2, or TSX Asynchronous Abort, has been disclosed today that targets the Transactional Synchronization Extensions (TSX) feature in Intel processors.
Using this vulnerability, local attackers or malware can steal sensitive data from the operating system kernel or other processes.
Performance in modern CPUs is increased through speculative execution, a feature that runs instructions in advance of knowing if they are needed or not. If they are required, the task completes faster, otherwise the data is discarded.
Attacks that target this feature are called speculative execution side-channel attacks.
In May 2019, new speculative execution attacks called RIDL, Fallout, and ZombieLoad were disclosed that could allow a malicious program to steal sensitive data from memory locations that normally they could not access. This is demonstrated in the ZombieLoad video below.
While microcodes and software-based protections were released to mitigate these older vulnerabilities, it was disclosed today that a new version of the ZombieLoad attacks can bypass current defenses and even affect processors in the Intel Cascade Lake CPU family.
