CVE-2021-41106

Severity CVSS v4.0:

Pending analysis

Type:

CWE-345 Insufficient Verification of Data Authenticity

Publication date:

28/09/2021

Last modified:

18/11/2025

Description

JWT is a library to work with JSON Web Token and JSON Web Signature. Prior to versions 3.4.6, 4.0.4, and 4.1.5, users of HMAC-based algorithms (HS256, HS384, and HS512) combined with `Lcobucci\JWT\Signer\Key\LocalFileReference` as key are having their tokens issued/validated using the file path as hashing key - instead of the contents. The HMAC hashing functions take any string as input and, since users can issue and validate tokens, users are lead to believe that everything works properly. Versions 3.4.6, 4.0.4, and 4.1.5 have been patched to always load the file contents, deprecated the `Lcobucci\JWT\Signer\Key\LocalFileReference`, and suggest `Lcobucci\JWT\Signer\Key\InMemory` as the alternative. As a workaround, use `Lcobucci\JWT\Signer\Key\InMemory` instead of `Lcobucci\JWT\Signer\Key\LocalFileReference` to create the instances of one&#39;s keys.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 4.40 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): Low
Availability (A): None

Base Score 3.x

4.40

Severity 3.x

MEDIUM

Vector 2.0

AV:L/AC:L/Au:N/C:N/I:P/A:N CVSS v2.0 Severity and Metrics:

Base Score: 2.10 LOW
Vector: AV:L/AC:L/Au:N/C:N/I:P/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): None
Integrity (I): Physical
Availability (A): None

Base Score 2.0

2.10

Severity 2.0

LOW

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:lcobucci:jwt::::::::	3.4.0 (including)	3.4.6 (excluding)
cpe:2.3:a:lcobucci:jwt::::::::	4.0.0 (including)	4.0.4 (excluding)
cpe:2.3:a:lcobucci:jwt::::::::	4.1.0 (including)	4.1.5 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-41106

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools