Security Threat Seen In Intel's Hyper-Threading Technology

"Hyper-Threading, as currently implemented on Intel Pentium Extreme Edition, Pentium 4, Mobile Pentium 4, and Xeon processors, suffers from a serious security flaw," said Colin Percival, a 23-year-old Ph.D. student from Vancouver, British Columbia, in a presentation on Friday (May 13).

"This flaw permits local information disclosure, including allowing an unprivileged user to steal an RSA private key being used on the same machine. Administrators of multi-user systems are strongly advised to take action to disable Hyper-Threading immediately," Percival said during the BSDCan 2005 conference in Ottawa.

The paper, entitled "Cache Missing for Fun and Profit," centers around Hyper-Threading, which allows multi-threaded applications to execute threads in parallel on a single CPU.

Percival's paper "outlines how a malicious thread can access areas of memory being run by other threads, perhaps to steal important things like cryptographic keys," according to the Geek.com Web site.

"Such a 'Spy' process could covertly monitor other threads, stealing information by forcing particular bits of cache memory to behave in a predictable fashion," according to the Web site. "Such a thread would not require any particular root or administrative privileges to run, and could be executed by an ordinary user."