CVE-2022-33986 — DMA attacks on the parameter buffer used by the VariableRuntimeDxe software SMI

DMA attacks on the parameter buffer used by the VariableRuntimeDxe software SMI handler could lead to a TOCTOU attack. DMA attacks on the parameter buffer used by the software SMI handler used by the driver VariableRuntimeDxe could lead to a TOCTOU attack on the SMI handler and l

01What is this vulnerability?

DMA attacks on the parameter buffer used by the VariableRuntimeDxe software SMI handler could lead to a TOCTOU attack. DMA attacks on the parameter buffer used by the software SMI handler used by the driver VariableRuntimeDxe could lead to a TOCTOU attack on the SMI handler and lead to corruption of SMRAM. This issue was discovered by Insyde engineering during a security review. This issue is…

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

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: 2022-11-14T00:00:00.000Z
• Last modified: 2025-04-30T19:56:45.263Z

09References

• www.insyde.com — https://www.insyde.com/security-pledge
• www.insyde.com — https://www.insyde.com/security-pledge/SA-2022056