1.5 KiB
CVE-2023-23583: microcode_ctl: Intel CPUs: execution of MOVSB instructions with redundant REX prefix leads to unintended system behavior
Summary
As described by Intel:
Under certain microarchitectural conditions, Intel has identified cases where execution of an instruction (REP MOVSB) encoded with a redundant REX prefix may result in unpredictable system behavior resulting in a system crash/hang, or, in some limited scenarios, may allow escalation of privilege from CPL3 to CPL0.
and by Red Hat:
A security vulnerability was found in some Intel processors. Execution of REP MOVSB instructions with a redundant REX prefix may result in execution continuing at an incorrect EIP address after a micro-architectural event occurs, potentially allowing privilege escalation, information disclosure and/or a denial of service via local access.
as well as in CVE-2023-23583.
More detail is available via these links to Intel's website and in the public disclosure by Tavis Ormandy from Google.
Public disclosure date: November 14, 2023
EL9
Fixed in version: 4:20231114-1.el9_2.security available November 15, 2023
EL8
Not fixed yet, will fix.