CVE-2023-20558Network attack vector

Privilege escalation via SMM handler tampering

Published Mar 23, 2023 · Updated Feb 20, 2025

Privilege escalation in AMD Ryzen and Threadripper firmware allows remote authenticated users to tamper with an AmdCpmOemSmm SMM handler. AMD identifies insufficient control-flow management in AmdCpmOemSmm but has not published the specific flawed operation or input path. Existing privileged access is required, and successful exploitation crosses into SMM to elevate privileges and compromise firmware-protected execution.

CVSS severity8.8
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Privilege escalation in AMD Ryzen and Threadripper firmware allows remote authenticated users to tamper with an AmdCpmOemSmm SMM handler. AMD identifies insufficient control-flow management in AmdCpmOemSmm but has not published the specific flawed operation or input path. Existing privileged access is required, and successful exploitation crosses into SMM to elevate privileges and compromise firmware-protected execution.

The record

CVE
CVE-2023-20558
Published
Mar 23, 2023
Updated
Feb 20, 2025
Vendor
AMD
Product
2nd Gen AMD Ryzen Threadripper Processors
Classifications
CWE-670, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 20, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 vectornetwork
Required privilegesauthenticated

What is affected?

AMD · 2nd Gen AMD Ryzen Threadripper Processorsversion=Various
AMD · AMD Ryzen 4000 Series Processorsversion=various
AMD · AMD Ryzen 2000 Series Processorsversion=various
AMD · AMD Ryzen 5000 Series Processorsversion=various
AMD · AMD Ryzen 3000 Series Processorsversion=various
AMD · 3rd Gen AMD Ryzen Threadripper Processors (Castle Peak)version=various
AMD · AMD Ryzen Threadripper PRO Processorsversion=various

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation
T1068Exploitation for Privilege Escalation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo