https://twitter.com/_markel___/status/1373059797155778562
Wow, we ([email protected]_max and @_Dmit) have found two undocumented x86 instructions in Intel CPUs which completely
control microarchitectural state (yes, they can modify microcode)
https://twitter.com/_markel___/status/1373059799307390981
They're decoded in all modes (even in User Mode) but the ucode in MSROM
throws #UD if not in Red Unlocked state. All details a little later...
挖出了Intel有未被记载公开的指令可以直接修改microcode怎么执行
所以理论上可以透过这两个指令 直接底层修改指令怎么执行
(当然这是很底层的东西 但就是个漏洞 有可能直接变更怎么拆解CISC指令成microcode)
晚点他会有更多资讯公布