CVE-2023-20577 — A heap overflow in SMM module may allow an attacker with access to a second vuln

A heap overflow in SMM module may allow an attacker with access to a second vulnerability that enables writing to SPI flash, potentially resulting in arbitrary code execution.

01What is this vulnerability?

A heap overflow in SMM module may allow an attacker with access to a second vulnerability that enables writing to SPI flash, potentially resulting in arbitrary code execution.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

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: 2026-09-02T20:17:34.093
• Last modified: 2026-09-04T20:17:20.570

09References

• www.amd.com — https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7009.html