Cyber Resilience

CVE-2023-20520

Critical

Published: 09 May 2023

Published
09 May 2023
Modified
28 January 2025
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0064 71.1th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-20520 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Amd Epyc 72F3 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 28.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potentially leading to arbitrary code execution.

CWE(s)
CWE-787

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

amd
epyc 72f3 firmware
milanpi_1.0.0.5
amd
epyc 7313 firmware
milanpi_1.0.0.5
amd
epyc 7313p firmware
milanpi_1.0.0.5
amd
epyc 7343 firmware
milanpi_1.0.0.5
amd
epyc 7373x firmware
milanpi_1.0.0.5
amd
epyc 73f3 firmware
milanpi_1.0.0.5
amd
epyc 7413 firmware
milanpi_1.0.0.5
amd
epyc 7443 firmware
milanpi_1.0.0.5
amd
epyc 7443p firmware
milanpi_1.0.0.5
amd
epyc 7453 firmware
milanpi_1.0.0.5
+53 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References