New Class of CPU Flaws Affect Almost Every Intel Processor Since 2011

New Class of CPU Flaws Affect Almost Every Intel Processor Since 2011

Academic researchers today disclosed details of the newest class of speculative execution side-channel vulnerabilities in Intel processors that impacts all modern chips, including the chips used in Apple devices.

After the discovery of Spectre and Meltdown processor vulnerabilities earlier last year that put practically every computer in the world at risk, different classes of Spectre and Meltdown variations surfaced again and again.

Now, a team of security researchers from multiple universities and security firms has discovered different but more dangerous speculative execution side-channel vulnerabilities in Intel CPUs.

The newly discovered flaws could allow attackers to directly steal user-level, as well as system-level secrets from CPU buffers, including user keys, passwords, and disk encryption keys.

Speculative execution is a core component of modern processors design that speculatively executes instructions based on assumptions that are considered likely to be true. If the assumptions come out to be valid, the execution continues, otherwise discarded.


Dubbed Microarchitectural Data Sampling (MDS attacks), the newest class of vulnerabilities consist of four different flaws, which, unlike existing attacks that leak data stored in CPU caches, can leak arbitrary in-flight data from CPU-internal buffers, such as Line Fill Buffers, Load Ports, or Store Buffers.

"The new vulnerabilities can be used by motivated hackers to leak privileged information data from an area of the memory that hardware safeguards ..