CVE-2021-40327

Name: CVE-2021-40327
Creator: NVD / NIST
Published: 2022-01-13T16:15:07.993+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 1.19%

Last modified Jun 17, 2026

CVE-2021-40327 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. Trusted Firmware-M (TF-M) 1.4.0, when Profile Small is used, has incorrect access control. NSPE can access a secure key (held by the Crypto service) based solely on knowledge of its key ID. EPSS estimates a 1.19% chance of exploitation in the next 30 days.

Description

Trusted Firmware-M (TF-M) 1.4.0, when Profile Small is used, has incorrect access control. NSPE can access a secure key (held by the Crypto service) based solely on knowledge of its key ID. For example, there is no authorization check associated with the relationship between a caller and a key owner.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

1.19%

64.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Trustedfirmware	Trusted Firmware-M	1.4.0

References

https://developer.arm.com/support/arm-security-updatesThird Party Advisory
https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/Patch, Vendor Advisory
https://tf-m-user-guide.trustedfirmware.org/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.htmlPatch, Vendor Advisory
https://developer.arm.com/support/arm-security-updatesThird Party Advisory
https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/Patch, Vendor Advisory
https://tf-m-user-guide.trustedfirmware.org/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.htmlPatch, Vendor Advisory

Timeline

Published: Jan 13, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40327?

How severe is CVE-2021-40327?

CVE-2021-40327 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 1.19% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40327?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40327?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST