Intel Has No Plans To Patch TLBleed Hyper-Threading CPU Exploit, Here's Why

ntel and its partners have been busy mitigating Spectre and Meltdown, which are two types of speculative side-channel CPU attacks that, if exploited, could potentially expose a user's sensitive data. Most of the mitigations have already been put in place. Other similar vulnerabilities have started to emerge, however, including one that has been dubbed TLBleed. Unlike Spectre and Meltdown though, Intel is not planning on mitigating TLBleed.

Details of the flaw will be presented at the Black Hat USA 2018 conference in early August at Mandalay Bay in Las Vegas. The organization refers to TLBleed as a "novel side-channel attack" that is capable of bypassing several proposed CPU case side-channel protections.

"Our TLBleed exploit successfully leaks a 256-bit EdDSA key from cryptographic signing code, which would be safe from cache attacks with cache isolation turned on, but would no longer be safe with TLBleed. We achieve a 98% success rate after just a single observation of signing operation on a co-resident hyperthread and just 17 seconds of analysis time. Further, we show how another exploit based on TLBleed can leak bits from a side-channel resistant RSA implementation. We use novel machine learning techniques to achieve this level of performance," Black Hat states.

According to The Register, researchers at the Systems and Network Security Group at Vrije Universiteit Amesterdam in the Netherlands say they have been able to leverage TLBleed to expose crypto keys from another running program in 99.8 percent of tests on an Intel Skylake Core i7-6700K processor, 98.2 percent of tests on a Broadwell Xeon E5-2620 vr server chip, and 99.8 percent of tests on a Coffee Lake processor

https://hothardware.com/news/intel-no-plans-patch-tlbleed-hyper-threading-cpu-exploit