Epyc 72f3 FirmwareOperating system · Amd

CVE-2023-20520

CRITICAL · 9.8 CVSS v3.1 Published 2023-05-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potentially leading to arbitrary code execution.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Improper access control in an ASP Bootloader allows corruption of the return address, causing a stack-based buffer overflow that can lead to arbitrary code execution. This is a memory corruption vulnerability in the early boot phase of the system.

MitigationApply vendor-provided firmware patches to the bootloader; verify patch integrity before deployment; test thoroughly in staging environments due to the critical nature of bootloader updates.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Epyc 72f3 FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7313 FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7313p FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7343 FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7373x FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 73f3 FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7413 FirmwareOperating system
Affected:= milanpi_1.0.0.5
Epyc 7443 FirmwareOperating system
Affected:= milanpi_1.0.0.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the AMD EPYC processor model
    Run 'dmidecode -t processor' or check system documentation to determine the exact processor model number (e.g., Epyc 72f3, 7313, 7313p, 7343, 7373x, 73f3, 7413, or 7443)
    Affected if The processor model matches one of the affected models listed in the CVE
  2. Retrieve the current firmware version
    Use 'dmidecode -s bios-version' or access the BMC/IPMI interface to query the firmware version string. For AMD EPYC Milan processors, look for a version string containing 'milanpi_'.
    Affected if The firmware version string equals milanpi_1.0.0.5 exactly
  3. Verify the boot component version
    Check the ASP Bootloader version through the BMC firmware inventory or by inspecting the boot log for a 'milanpi' or 'ASP Bootloader' version entry during system startup
    Affected if The ASP Bootloader component reports version 1.0.0.5 from the milanpi baseline
  4. Confirm the boot phase vulnerability context
    Review the system boot logs (via BMC or serial console) for any anomalies in the early boot phase related to the bootloader (ASP Bootloader)
    Affected if The system boots using the vulnerable milanpi_1.0.0.5 bootloader firmware with no patch applied

A system is affected if it uses an AMD EPYC Milan processor (72f3, 7313, 7313p, 7343, 7373x, 73f3, 7413, or 7443) with firmware version exactly milanpi_1.0.0.5 containing the vulnerable ASP Bootloader.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-provided firmware patches to the bootloader; verify patch integrity before deployment; test thoroughly in staging environments due to the critical nature of bootloader updates.

Fix this in Epyc 72f3 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing24.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,520
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-20520 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data