CVE-2022-40246 — A potential attacker can write one byte by arbitrary address at the time of the

A potential attacker can write one byte by arbitrary address at the time of the PEI phase (only during S3 resume boot mode) and influence the subsequent boot stages. This can lead to the mitigations bypassing, physical memory contents disclosure, discovery of any secrets from any

01What is this vulnerability?

A potential attacker can write one byte by arbitrary address at the time of the PEI phase (only during S3 resume boot mode) and influence the subsequent boot stages. This can lead to the mitigations bypassing, physical memory contents disclosure, discovery of any secrets from any Virtual Machines (VMs) and bypassing memory isolation and confidential computing boundaries. Additionally, an attacker…

02Affected products

Vendor	Product	Versions
AMI	Aptio	5.x

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: 2022-09-20T17:35:33.274Z
• Last modified: 2025-05-28T18:41:09.998Z

09References

• www.ami.com — https://www.ami.com/security-center/
• www.binarly.io — https://www.binarly.io/advisories/BRLY-2022-014