Stefan Mileschin

All Chipzilla chips open to new Spoiler non-Spectre attack

AMD might scoop up some more custom after researchers have discovered a new flaw affecting all Intel chips due to the way they carry out speculative execution for CPU performance gains.

Dubbed Spoiler, the new hack abuses speculative execution in Intel chips to leak secrets. IT targets a different area of the processor called the Memory Order Buffer, which is used to manage memory operations and is tightly coupled with the cache.

Researchers from Worcester Polytechnic Institute, Massachusetts, and the University of Lübeck in north Germany detail the attack in a new paper, 'Spoiler: Speculative load hazards boost Rowhammer and cache attacks'. The paper was released this month.

The researchers explain that Spoiler is not a Spectre attack, so it is not affected by Intel's mitigations for it, which otherwise can prevent other Spectre-like attacks such as SplitSpectre.

"The root cause for Spoiler is a weakness in the address speculation of Intel's proprietary implementation of the memory subsystem, which directly leaks timing behaviour due to physical address conflicts. Existing Spectre mitigations would therefore not interfere with Spoiler," they write.

They looked for the same weakness in Arm and AMD processor cores but didn't find the same behaviour that is present in Intel chips. Spoiler depends on "a novel microarchitectural leakage, which reveals critical information about physical page mappings to userspace processes".

"The leakage can be exploited by a limited set of instructions, which is visible in all Intel generations starting from the 1st generation of Intel Core processors, independent of the OS, and also works from within virtual machines and sandboxed environments."

https://fudzilla.com/news/pc-hardwar...intel-chip-bug