CVE-2020-27211Public exploit

Firmware readout via boot-time voltage fault injection

Published May 21, 2021 · Updated Aug 4, 2024

Physical side-channel weakness in Nordic Semiconductor nRF52840 through 2020-10-19 allows physically proximate attackers to read firmware. A short voltage pulse on the DEC1 power rail during boot disrupts APPROTECT initialization and re-enables the AHB-AP SWD debug port. Physical board access and fault-injection equipment are required; exploitation permits flash dumping, memory and register writes, and CPU execution control.

CVSS severity5.7
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Physical side-channel weakness in Nordic Semiconductor nRF52840 through 2020-10-19 allows physically proximate attackers to read firmware. A short voltage pulse on the DEC1 power rail during boot disrupts APPROTECT initialization and re-enables the AHB-AP SWD debug port. Physical board access and fault-injection equipment are required; exploitation permits flash dumping, memory and register writes, and CPU execution control.

The record

CVE
CVE-2020-27211
Published
May 21, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-203, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.7National Vulnerability DatabaseCVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
3.3National Vulnerability DatabaseAV:L/AC:M/Au:N/C:P/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-203Observable Discrepancy
T1200Hardware Additions

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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