Intel CPUs Reportedly Vulnerable To New "SPOILER" Speculative Attack

SPOILER is the newest speculative attack affecting Intel's micro-architecture.

Researchers out of the Worcester Polytechnic Institute and University of Lubeck discovered this new speculative attack dubbed SPOILER, Speculative Load Hazards Boost Rowhammer and Cache Attacks.

Intel was notified of this issue a few months ago but no software/hardware fix appears ready yet, while the researchers claim there might not be an effective software solution available at least anytime soon -- and any mitigation would likely come at a performance cost, as we've seen with Spectre and Meltdown over the past year. AMD and ARM CPUs aren't believed to be impacted by SPOILER.

In this work, we are the first to show that the dependency resolution logic that serves the speculative load can be ex-ploited to gain information about the physical page mappings. Microarchitectural side-channel attacks such as Rowhammer and cache attacks rely on the reverse engineering of the virtual-to-physical address mapping. We propose the SPOILER attack which exploits this leakage to speed up this reverse engineer-ing by a factor of 256. Then, we show how this can improve the Prime+Probe attack by a 4096 factor speed up of the eviction set search, even from sandboxed environments like JavaScript. Finally, we improve the Rowhammer attack by showing how SPOILER helps to conduct DRAM row conflicts deterministically with up to 100% chance, and by demonstrat-ing a double-sided Rowhammer attack with normal user’s privilege. The later is due to the possibility of detecting contiguous memory pages using the SPOILER leakage.

The SPOILER research paper can be read here.

Update: An Intel spokesperson has provided us with the following statement:

"Intel received notice of this research, and we expect that software can be protected against such issues by employing side channel safe software development practices. This includes avoiding control flows that are dependent on the data of interest. We likewise expect that DRAM modules mitigated against Rowhammer style attacks remain protected. Protecting our customers and their data continues to be a critical priority for us and we appreciate the efforts of the security community for their ongoing research."