CVE-2020-12788
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 · uneditedCMAC verification functionality in Microchip Atmel ATSAMA5 products is vulnerable to vulnerable to timing and power analysis attacks.
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 confidenceCMAC (Cipher-based Message Authentication Code) verification in Microchip Atmel ATSAMA5 products leaks cryptographic secrets through timing and power analysis side-channels. An attacker with physical proximity could potentially recover authentication keys by measuring execution time or power consumption patterns during CMAC operations.
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 Atmel SAMA5 hardware modelLocate the chip marking on the MCU or check device documentation/datasheet for the exact model number (e.g., ATSAMA5D21C-CU, ATSAMA5D22C-CN, ATSAMA5D23C-CNR)Affected if The model matches any of: SAMA5d21c Cu, SAMA5d21c Cur, SAMA5d22c Cn, SAMA5d22c Cnr, SAMA5d22c Cu, SAMA5d22c Cur, SAMA5d23c Cn, SAMA5d23c Cnr
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Confirm the firmware versionAccess the device firmware information via bootloader, debug interface, or system information command (consult device documentation for specific method)Affected if Any firmware version is installed on the affected models (all versions are vulnerable)
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Determine if CMAC authentication is in useReview application configuration, security settings, or firmware image to identify whether CMAC-based message authentication is enabled for any cryptographic operationsAffected if CMAC verification is actively used for authentication in the system
You are affected if you are running any firmware version on an ATSAMA5d21c, ATSAMA5d22c, or ATSAMA5d23c variant (Cu/Cur/Cn/Cnr) and CMAC authentication is enabled in your system, as the side-channel vulnerability exists regardless of version.
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 dataContact Microchip for patched firmware addressing the side-channel leakage; until available, employ physical access controls and monitor for anomalous device access patterns.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 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 $12,352.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-12788 — 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-2020-12788 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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- 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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