Time-of-check Time-of-use (TOCTOU) Race Condition in 2nd Gen AMD EPYC Processors and 3rd Gen AMD EPYC Processors - CVE-2021-26347
Published: May 25, 2022
Vulnerability identifier: #VU63679
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-26347
CWE-ID: CWE-367
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: AMD
Affected software:
2nd Gen AMD EPYC Processors
3rd Gen AMD EPYC Processors
2nd Gen AMD EPYC Processors
3rd Gen AMD EPYC Processors
Detailed vulnerability description
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a race condition in the System Management Unit (SMU). A local user can force the DMA (Direct Memory Access) to reference an invalid DRAM address and perform a denial of service attack.
How to mitigate CVE-2021-26347
Install updates from vendor's website.