CVE-2021-40327 json
Trusted Firmware-M (TF-M) 1.4.0, when Profile Small is used, has incorrect access control.
published 4y ago modified 4mo ago also EUVD-2021-27507
- cvss
- 5.9
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 69%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2021-40327 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
1.23% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVD | 2.0 | 2.6 | AV:N/AC:H/Au:N/C:P/I:N/A:N |
Classification
- Weakness
-
- CWE-862 Missing Authorization
References
-
git.trustedfirmware.org
/TF-M/trusted-firmware-m.git/
patch, vendor-advisory
-
tf-m-user-guide.trustedfirmware.org
/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.html
patch, vendor-advisory
-
developer.arm.com
/support/arm-security-updates
third-party-advisory
Sources
- CVE List CVE-2021-40327
- NVD CVE-2021-40327
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