CVE-2023-20566

Guest memory corruption via unvalidated ASP address

Published Nov 14, 2023 · Updated Dec 3, 2024

Improper address validation in AMD EPYC PI firmware allows local users with administrative privileges to alter SEV-SNP guest memory. The AMD Secure Processor fails to validate an address while Secure Nested Paging is enabled, permitting writes that compromise guest memory integrity. Exploitation requires local, highly privileged access and a difficult execution path; confidentiality and availability impacts are not reported.

CVSS severity5.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper address validation in AMD EPYC PI firmware allows local users with administrative privileges to alter SEV-SNP guest memory. The AMD Secure Processor fails to validate an address while Secure Nested Paging is enabled, permitting writes that compromise guest memory integrity. Exploitation requires local, highly privileged access and a difficult execution path; confidentiality and availability impacts are not reported.

The record

CVE
CVE-2023-20566
Published
Nov 14, 2023
Updated
Dec 3, 2024
Vendor
AMD
Product
4th Gen AMD EPYC Processors
Classifications
T1565
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Nov 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=various

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

AMD · 4th Gen AMD EPYC Processorsversion=various
AMD · AMD EPYC Embedded 9003version=various
Advanced Micro Devices, Inc. · AMD EPYC Embedded 7003 Series Processorsversion=various
AMD · 3rd Gen AMD EPYC Processorsversion=various

Published CVSS scores

5.3Advanced Micro Devices, Inc.CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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