SMT vulnerability 'not critical' - Intel • Channel Register

SMT vulnerability 'not critical' - Intel

Got to 'own' a machine to make use of it

By Tony Smith • Get more from this author

Posted in PC Builder, 16th May 2005 10:43 GMT

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Intel has pledged to work with operating system vendors to prevent its HyperThreading system being used by malware to snoop for sensitive data.

However, it claimed the problem, revealed in a paper published last week, is a minor one: it can only be exploited once the security of the targeted desktop or server has already been compromised.

The chip giant was also quick to point out that HT-enabled CPUs are not the only ones vulnerable to the newly exposed attack. It can be brought to bear against any processor with that can do simultaneous multi-threading. Dual-cores too, it seems, are vulnerable.

The vulnerability arises because code running on one thread can access cache and memory being used by another thread. If the former's a crypto-key sniffer and the other's caching said key, the first thread can copy the information then relay it to another machine. You can read researcher Colin Percival's paper on the subject here (PDF).

Intel said it had already been notified of the problem before Percival's paper was posted on the web last week. The chip maker said it was working with a number of OS vendors to "fix the issues".

"The flaw is not considered critical, but it will be fixed in subsequent updates to the Microsoft and Linux operating systems," Intel said. ®