Vulnerability Report

CVE-2021-40327

Title: Trustedfirmware Trusted Firmware-M Auth Bypass

Other

Proof Of Concept

No public PoC currently indexed for CVE-2021-40327.

CWE Category CWE-862

Published Date Jan 13, 2022

Modified Date Jun 05, 2026

Exploit Status Not Found

Score 5.9 CVSS v3.1

Exploit Probability (EPSS)

1.19%

Vulnerability Summary

CVE-2021-40327: 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.

Impacted Vendors

linaro 1

trustedfirmware 1

Reference Links

https://developer.arm.com/support/arm-security-updates https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/ https://tf-m-user-guide.trustedfirmware.org/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.html https://developer.arm.com/support/arm-security-updates https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/ https://tf-m-user-guide.trustedfirmware.org/docs/security/security_advisories/profile_small_key_id_encoding_vulnerability.html

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

5.9

Attack Vector

NETWORK

Complexity

HIGH

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

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

CVSS v2.0

Source Entity [email protected]

Severity LOW

2.6

Access Vector

N/A

Authentication

N/A

RAW VECTOR AV:N/AC:H/Au:N/C:P/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-40327 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

June 05, 2026 MODIFIED

Vulnerability data updated via NVD.

November 21, 2024 MODIFIED

Vulnerability data or affected products updated.

January 13, 2022 PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity HIGH

Privileges N/A

Interaction NONE

CVSS Vector String


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

Affected Stack

No specific products linked.