Overview
Modern CPUs have speculative execution capabilities, which improves processor performance. Depending on the design and architecture of the CPU, speculative execution can introduce side-channel-attack vulnerabilities.
Known Vulnerabilities
Notes
Spectre V1 has been demonstrated to bypass protections provided by Intel SGX. Intel has updated the SGX SDK to mitigate these vulnerabilities when the SGX enclaves are rebuilt.
https://software.intel.com/sites/default/files/managed/e1/ec/SGX_SDK_Developer_Guidance-CVE-2017-5753.pdf
Spectre V1 has also been demonstrated to access protections provided by the System Management Range Register (SMRR) to access protected System Management Mode (SMM) memory.
https://blog.eclypsium.com/2018/05/17/system-management-mode-speculative-execution-attacks/