CVE-2020-27211
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 · uneditedNordic Semiconductor nRF52840 devices through 2020-10-19 have improper protection against physical side channels. The flash read-out protection (APPROTECT) can be bypassed by injecting a fault during the boot phase.
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 nRF52840's flash read-out protection (APPROTECT) can be bypassed by injecting a fault (e.g., voltage glitching, electromagnetic fault injection) during the boot phase, allowing unauthorized extraction of firmware and sensitive data from the device's flash memory.
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<= 2020-10-19CVSS 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
- Physical
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/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 hardware platformVerify that your device uses the Nordic Semiconductor nRF52840 chipset. This information is typically found in the device's hardware specifications, schematics, or PCB markings.Affected if The device is not based on the nRF52840 chipset, then this CVE does not apply.
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Determine the installed firmware versionRead the firmware version from the device's bootloader information, debug interface (SWD/JTAG), or check the firmware binary metadata. Use Nordic's nRF Connect SDK tools or read the UICR register via nrfjprog if you have debug access.Affected if The firmware version or build date cannot be determined or is earlier than or equal to 2020-10-19.
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Check the APPROTECT configuration statusRead the UICR (User Information Configuration Registers) via nrfjprog --memrd or check the APPROTECT setting in the device's security configuration. The APPROTECT bit should be set to enabled for flash read-out protection.Affected if APPROTECT is disabled or was found to be bypassable during boot sequence testing.
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Verify the firmware build dateIf version strings are unavailable, check the firmware binary's creation timestamp or consult release notes from the firmware vendor. The vulnerability is present in builds released on or before October 19, 2020.Affected if The firmware was compiled or released on or before 2020-10-19.
You are affected if your device uses the nRF52840 chipset with firmware dated 2020-10-19 or earlier, and the APPROTECT mechanism can be bypassed through fault injection during the boot phase.
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 dataApply any available firmware updates from Nordic Semiconductor; if no update exists, implement physical security controls to prevent unauthorized access and consider using an external secure element for critical secrets.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-27211 — 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-2020-27211 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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