Servers that use Intel's hyperthreading processor technology could allow a hacker to steal security keys and other information.
A security researcher has reported the flaw and Intel and Microsoft are working on a fix for the problem.
Hyperthreading allows live applications to take advantage of unused execution units in a processor to increase processor productivity.
Independent security researcher Colin Percival said that a hacker could take advantage of the fact that the different multiple processes shared access to a hyperthreading chip’s cache memory.
A hacker could capture information left behind in the cache while the chip moved onto the next process, he said. This opportunity doesn’t exist in a traditional single-threaded chip, which clears the cache before moving onto the next process.
By repeatedly capturing information in previous used areas of the chip’s cache, a hacker could build up sensitive pieces of information, including security keys.
Intel's Pentium 4 and Xeon processors use hyperthreading technology.
Intel said it did not consider the flaw critical as it only allowed hackers access to the hyperthreading vulnerability once the server had been compromised through a previous attack.
More details on the vulnerability are available at: