CVE-2021-41106

4.4 MEDIUM
Published: September 28, 2021 Modified: November 18, 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's keys.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/lcobucci/jwt/commit/8175de5b841fbe3fd97d2d49b3fc15c4ecb39a73
Source: security-advisories@github.com
Patch Third Party Advisory
https://github.com/lcobucci/jwt/commit/c45bb8b961a8e742d8f6b88ef5ff1bd5cca5d01c
Source: security-advisories@github.com
Patch Third Party Advisory
https://github.com/lcobucci/jwt/security/advisories/GHSA-7322-jrq4-x5hf
Source: security-advisories@github.com
Patch Third Party Advisory
https://github.com/lcobucci/jwt/commit/8175de5b841fbe3fd97d2d49b3fc15c4ecb39a73
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory
https://github.com/lcobucci/jwt/commit/c45bb8b961a8e742d8f6b88ef5ff1bd5cca5d01c
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory
https://github.com/lcobucci/jwt/security/advisories/GHSA-7322-jrq4-x5hf
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.4 / 10.0
EPSS (Exploit Probability)
0.0%
10th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

lcobucci