microcode_ctl: Intel Processors: Escalation of privilege due to default cryptographic key

Use of Default Cryptographic Key in the hardware for some Intel(R) Pentium(R) Processor Silver Series, Intel(R) Celeron(R) Processor J Series, Intel(R) Celeron(R) Processor N Series may allow an escalation of privilege. Hardware reverse engineer adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via physical access when attack requirements are present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (none) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts.