Intel chip flaw gets double exposure

Security researchers are due to publish research on how an Intel chip flaw might be used for potentially malign purposes on Thursday.

Both Joanna Rutkowska, of Blue Pill renown, and Loic Duflot have separately announced plans to release a research paper and proof of concept exploit code on how an Intel CPU caching vulnerability might be misused. The flaw creates a potential means to attack the SMM (System Management Mode) of systems. Duflot will present his work at CanSEcWest in Vancover while Rutkowska is due to publish a paper on the same subject, also on Thursday.

"The attack allows for privilege escalation from Ring 0 to the SMM on many recent motherboards with Intel CPUs," Rutkowska, chief exec of of Invisible Things Lab explains.

The Intel caching hack is all the more serious because it burrows into SMM space, which is more privileged than a hypervisor area. As such it is a possible mechanism for creating "incredibly stealthy" rootkits, security blogger James Heary adds.

Invisible Things Lab's paper touches on the long-running debate about security disclosure. According to Rutkowska, Intel's own employees first wrote about how this class of CPU caching vulnerability might be exploited back in early 2005.

Duflot came across the problem and was the first to write a proof-of-concept exploit in October 2008. Rutkowska independently discovered the same issue a couple of months later.

"If there is a bug somewhere and if it stays unpatched for enough time, it is almost guaranteed that various people will (re)discover and exploit it, sooner or later," Rutkowska writes. "So, don't blame researchers that they find and publish information about bugs — they actually do a favor to our society." ®