CVE-2021-29415

The elliptic curve cryptography (ECC) hardware accelerator, part of the ARM® TrustZone® CryptoCell 310, contained in the NordicSemiconductor nRF52840 through 2021-03-29 has a non-constant time ECDSA implemenation. This allows an adversary to recover the private ECC key used during an ECDSA operation.

Published: 2021-05-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-29415 is rated Low Risk (28.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.27%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-29415

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.08% 0.27% +0.19%
2 2025-03-30 0.16% 0.08% -0.08%
3 2025-03-29 — 0.16% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29415

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-29415

Affected software / configurations for CVE-2021-29415

Vendor Product Version Raw CPE
nordicsemi nrf52840_firmware <= 2021-03-29 cpe:2.3:o:nordicsemi:nrf52840_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-29415

cvelogic Threat Intelligence