CVE-2021-40327
Trusted Firmware-M (TF-M) 1.4.0, when Profile Small is used, has incorrect access control. NSPE...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.9
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.
- Record
CVE-2021-40327- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 2.6 Low
AV:N/AC:H/Au:N/C:P/I:N/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-40327- Updated
- 2026-11-02
EUVDEUVD-2021-27507 No score
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.
- Record
EUVD-2021-27507- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p88f-g9m7-hv9c
5.9
Trusted Firmware-M (TF-M) 1.4.0, when Profile Small is used, has incorrect access control. NSPE...
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.
- Record
GHSA-p88f-g9m7-hv9c- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
OSV
5.9
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.
- Record
CVE-2021-40327- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-40327
5.9
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.
- Record
UBUNTU-CVE-2021-40327- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-40327 is a medium vulnerability (CVSS 5.9) in Trustedfirmware Trusted Firmware-m, published January 13, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.23%, the 69th percentile. No source names a fixed version.
References
developer.arm.com/support/arm-security-updates
git.trustedfirmware.org/TF-M/trusted-firmware-m.git
tf-m-user-guide.trustedfirmware.org/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.html
nvd.nist.gov/vuln/detail/CVE-2021-40327
github.com/advisories/GHSA-p88f-g9m7-hv9c
ubuntu.com/security/CVE-2021-40327
cve.org/CVERecord?id=CVE-2021-40327