After the exposure of ghost and fuse vulnerabilities, the security vulnerabilities of Intel and AMD processors suddenly increased a lot, in fact, mainly related research is more in-depth, and the new vulnerability is similar in the basic principle. In fact, Intel, AMD, ARM, IBM and other chip giants are very welcome and support such vulnerability security research, help to improve the security of their own products, and even funded a number of research projects, the recent exposure of the LVI vulnerability is a typical.
LVI’s full name is Load Value Injection, which is roughly what loading value injection means, first discovered by security research firm BitDefender and reported to Intel on February 10 this year.
It has affected the vast majority of Intel Sandy Bridge 2nd Generation Core products, with only Cascade Lake II Extended Toe, Coffee Lake 9th Generation Core Comet Tenth Generation Core Part Of Immunity, and Ice Lake Ten Core Completely Immunized.
The vulnerability could allow an attacker to bypass Intel SGX software protection extensions and steal sensitive information from processors, similar to ghost vulnerabilities, but Intel and BitDefender believe it is only a theoretical attack and does not have a substantial threat.
Intel said the affected product could only avoid the vulnerability by shutting down the hyperthread, but Intel also updated the SGX platform software and SDK development package to avoid potential security threats, simply adding an LFENCE directive wall before the affected instructions.
Intel’s previous security patches have often affected performance, but not by a large margin, what happens this time?
Phoronix found a Xeon E3-1275 v6 (Kaby Lake) that was tested in a Linux environment, including unpatched, pre-branch forecastloading LFENCE, loadled LFENCE before RET instructions, LFENCE executed after loading, and loaded LFENCE/RET/branch prediction.
It was found that the branch forecast and the RET directive before loading LFENCE had little impact, the performance loss of only 3%, 8%, but the latter two cases suffered heavy losses, as high as 77%.
This is not a night back to the liberation, directly back to the primitive society …
Fortunately, however, the LVI vulnerability has little impact on the average consumer, because mainstream PCs simply don’t use SGX, and enterprise users have to pay attention to It because they use SGX frequently, virtualization.