Security News > 2021 > August > Boffins find if you torture AMD Zen+, Zen 2 CPUs enough, they are vulnerable to Meltdown-like attack

Computer scientists at TU Dresden in Germany have found that AMD's Zen processor family is vulnerable to a data-bothering Meltdown-like attack after all.

In a paper [PDF] titled "Transient Execution of Non-Canonical Accesses," released via ArXiv, Saidgani Musaev and Christof Fetzer analyzed AMD Zen+ and Zen 2 chips - namely the Epyc 7262, Ryzen 7 2700X, and the Threadripper 2990WX - and found that they were able to adversely manipulate the operation of the CPU cores.

AMD claimed its processors were not affected by Meltdown.

"Unlike the previous AMD vulnerabilities, the flaw we report is the first flaw that proves that it is possible to force an illegal data flow between microarchitectural elements."

"The consequence of having a code snippet vulnerable to such behavior may allow an attacker to poison the transient execution of the AMD CPU from the microarchitectural element," the boffins said.

"When combined with specific software sequences, AMD CPUs may transiently execute non-canonical loads and store using only the lower 48 address bits potentially resulting in data leakage," the advisory says.

News URL

https://go.theregister.com/feed/www.theregister.com/2021/08/30/amd_meltdown_zen/