dbcve.org
Epyc 7h12 FirmwareOperating system · Amd

CVE-2023-20527

MEDIUM · 6.5 CVSS v3.1 Published 2023-01-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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 syscall input validation in the ASP Bootloader may allow a privileged attacker to read memory out-of-bounds, potentially leading to a denial-of-service.

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

This is a firmware vulnerability in the AMD ASP (Advanced Secure Processor) Bootloader. The improper syscall input validation allows a privileged attacker to perform out-of-bounds memory reads, potentially exposing sensitive data and causing denial-of-service. The issue stems from insufficient validation of user-supplied input to syscalls in the bootloader's syscall handling subsystem.

MitigationApply vendor-supplied firmware updates for the AMD ASP Bootloader that address input validation in syscall handlers. Since this affects a bootloader component, systems may require a firmware reflash and verification of the secure boot chain.

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 7h12 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7f72 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7f52 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7f32 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7742 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7702p FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7702 FirmwareOperating system
Affected:< romepi_1.0.0.c
Epyc 7662 FirmwareOperating system
Affected:< romepi_1.0.0.c

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 | grep -E "Model|Version"' or check system inventory to confirm the exact Epyc model (7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, or 7662)
    Affected if The processor is any of the listed Epyc models (7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, 7662)
  2. Check AMD ASP firmware version
    Use 'ls -la /sys/firmware/efi/efivars/Asps*' or check via BMC/IPMI: 'ipmitool raw <command>' to query the AMD Secure Processor firmware version. Alternatively, use 'dmidecode -t processor' or vendor-specific tools like AMD PSP firmware check utilities.
    Affected if The ASP firmware version is present and readable from the system
  3. Determine bootloader version
    Query the bootloader version from the ASP firmware. On systems with AMD Secure Processor diagnostic tools, run the vendor-provided tool to query the 'romepi' bootloader component version. Check BMC or BIOS logs for ASP bootloader version strings matching 'romepi'
    Affected if The bootloader component version is earlier than romepi_1.0.0.c or the version string is not present at all
  4. Verify syscall handler availability
    Check if the AMD ASP Bootloader syscall interface is exposed or accessible. Review system documentation to confirm whether user-mode or privileged code can invoke syscalls through the ASP bootloader interface. Inspect any exposed ASP syscall interfaces documented in system firmware or driver documentation.
    Affected if The system allows privileged or administrative code to invoke ASP bootloader syscalls, which would enable the out-of-bounds memory read condition
  5. Review secure boot and firmware integrity logs
    Check BIOS/UEFI and BMC logs for any anomalies related to ASP bootloader initialization, secure boot chain verification, or firmware version mismatches. Run 'journalctl -b | grep -i asp' or check BMC event logs for ASP-related entries.
    Affected if There are signs of firmware manipulation or the secure boot chain shows warnings related to the ASP bootloader component

A user is affected if they are running any of the listed AMD Epyc processors (7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, 7662) with an ASP bootloader firmware version earlier than romepi_1.0.0.c, and the system has privileged access to ASP syscall handlers enabled.

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-supplied firmware updates for the AMD ASP Bootloader that address input validation in syscall handlers. Since this affects a bootloader component, systems may require a firmware reflash and verification of the secure boot chain.

Fix this in Epyc 7h12 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,040
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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-2023-20527 in production — separate from our analysis above.

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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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