CVE-2020-12789
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 · uneditedThe Secure Monitor in Microchip Atmel ATSAMA5 products use a hardcoded key to encrypt and authenticate secure applets.
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 confidenceThe Secure Monitor in Microchip Atmel ATSAMA5 products uses a hardcoded cryptographic key to encrypt and authenticate secure applets. An attacker who discovers this key (through reverse engineering, firmware extraction, or other means) could create malicious applets that would be authenticated by the system, potentially leading to code execution in a privileged security context.
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 dataall versionsall versionsall versionsall versionsall versionsall versionsall versionsall versionsCVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Identify the exact ATSAMA5 device modelCheck the physical device marking or boot logs for the exact model number (e.g., SAMA5D21C Cu, SAMA5D22C Cnr, SAMA5D23C Cn)Affected if The device model matches any of the affected variants: SAMA5D21C, SAMA5D22C, or SAMA5D23C with suffixes Cu, Cur, Cn, or Cnr
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Verify the Secure Monitor feature is in useCheck if the Secure Monitor (SecureBoot or secure firmware update) is enabled in the device configuration or boot settingsAffected if Secure Monitor or secure boot functionality is enabled on the device
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Locate the Secure Monitor firmware imageAccess the device firmware (via debug interface, JTAG, or firmware dump) and locate the secure_monitor binary or flash memory region containing the Secure MonitorAffected if A firmware image containing the Secure Monitor component is present on the device
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Search for hardcoded cryptographic material in Secure Monitor binaryExtract the secure_monitor binary and perform static analysis (strings, hex dump) to locate any hardcoded 128-bit or 256-bit keys or authentication tokens used for applet signingAffected if A static cryptographic key value is found embedded in the Secure Monitor binary rather than being derived from hardware unique keys
The device is affected if it uses any ATSAMA5D21C/22C/23C variant and the Secure Monitor is enabled, since all firmware versions contain the hardcoded key.
Generated from the published advisory. Verify against your own configuration.
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 dataReplace the hardcoded key with securely generated, device-unique keys stored in protected hardware (e.g., eFuse, secure element) or implement proper key derivation based on device-specific secrets. Rotate keys and audit the secure monitor implementation.
- Consultation8.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $15,616.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-12789 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-12789 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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
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