CVE-2023-20558 — Insufficient control flow management in AmdCpmOemSmm may allow a privileged atta

Insufficient control flow management in AmdCpmOemSmm may allow a privileged attacker to tamper with the SMM handler potentially leading to an escalation of privileges.

01What is this vulnerability?

Insufficient control flow management in AmdCpmOemSmm may allow a privileged attacker to tamper with the SMM handler potentially leading to an escalation of privileges.

02Affected products

Vendor	Product	Versions
AMD	Ryzen™ 2000 Series	various
AMD	Ryzen™ 3000 Series	various
AMD	Ryzen™ 4000 Series	various
AMD	Ryzen™ 5000 Series	various
AMD	2nd Gen AMD Ryzen™ Threadripper™ Processor	Various
AMD	3rd Gen AMD Ryzen™ Threadripper™ Processors	various
AMD	Ryzen™ Threadripper™ PRO Processor	various

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-03-23T18:50:11.488Z
• Last modified: 2025-02-20T19:23:58.341Z

09References

• www.amd.com — https://www.amd.com/en/resources/product-security/bulletin/amd-sb-1027.html