dbcve.org
Ryzen 5500 FirmwareOperating system · Amd

CVE-2021-46755

HIGH · 7.5 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 →
84/100
Remediation priority · High
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
Failure to unmap certain SysHub mappings in error paths of the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious bootloader to exhaust the SysHub resources resulting in a potential 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 · high confidence

In the AMD Secure Processor (ASP) bootloader, certain SysHub memory mappings are not properly unmapped when error paths are executed during the boot process. An attacker capable of running a malicious bootloader can repeatedly trigger these error conditions without proper cleanup, exhausting SysHub resources and causing a denial of service.

MitigationApply the AMD firmware update for the Secure Processor when available. Until then, ensure physical security and chain-of-trust measures prevent execution of unauthorized bootloader code.

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
Ryzen 5500 FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5600 FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5600g FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5600x FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5700g FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5700x FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5800x3d FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6
Ryzen 5800x FirmwareOperating system
Affected:= comboam4_v2_pi_1.2.0.8= comboam4v2_pi_1.2.0.6

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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. Check the installed AMD Secure Processor firmware version
    Use the command 'wmic bios get version' or check the BIOS/UEFI setup screen for the firmware version. On AMD systems, the BIOS version often includes the PSP (Platform Security Processor) firmware indicator. Alternatively, use AMD Ryzen Master utility if available and look for the 'PSP' or 'Secure Processor' firmware version entry.
    Affected if The displayed firmware version matches 'comboam4_v2_pi_1.2.0.8' or 'comboam4v2_pi_1.2.0.6' exactly.
  2. Identify the specific Ryzen processor model
    Run 'wmic cpu get name' or check system information to confirm the exact Ryzen model number (e.g., Ryzen 5 5600X, Ryzen 7 5800X).
    Affected if The processor is one of: Ryzen 5500, 5600, 5600g, 5600x, 5700g, 5700x, 5800x3d, or 5800x.
  3. Check the combined BIOS/PSP firmware string
    Review the full BIOS version string shown in the UEFI/BIOS setup or via 'wmic bios get version'. AMD BIOS versions often embed the PSP firmware version within the larger BIOS version string.
    Affected if The string contains 'comboam4_v2_pi_1.2.0.8' or 'comboam4v2_pi_1.2.0.6'.
  4. Assess physical access risk
    Determine if the system could be accessed by an attacker capable of loading or modifying the bootloader. This is a prerequisite for exploitation, as the vulnerability requires running a malicious bootloader.
    Affected if The system has potential for unauthorized physical access or boot medium tampering.

The system is affected if it uses a Ryzen 5500/5600/5600g/5600x/5700g/5700x/5800x/5800x3d processor with AMD Secure Processor firmware version comboam4_v2_pi_1.2.0.8 or comboam4v2_pi_1.2.0.6 AND an attacker could run a malicious 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 the AMD firmware update for the Secure Processor when available. Until then, ensure physical security and chain-of-trust measures prevent execution of unauthorized bootloader code.

Fix this in Ryzen 5500 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
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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-2021-46755 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data