CVE intelligence and bounded remediation

CVE-2021-41106 — JWT is a library to work with JSON Web Token and JSON Web Signature

Medium CVSS 4.4

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.

Severity
Medium
CVSS
4.4 (3.1)
Published
2021-09-28
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-345

Affected products

  • lcobucci / jwt

Showing 1 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Supply-chain, dependency, build, and update integrity

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace affected packages, source archives, build actions, plugins, installers, and updates from declared source to deployed artifact.
  • Confirm provenance, signatures or digests, namespace ownership, lockfile resolution, registry configuration, and build-runner trust boundaries.
  • Inventory direct, transitive, vendored, generated, and bundled copies across releases and distribution channels.

Remediate safely

  • Move to a maintained trusted artifact or remove the dependency; pin immutable identities and verify provenance and integrity before use.
  • Regenerate lockfiles and artifacts in a clean isolated build, minimize build credentials and network access, and produce an updated software bill of materials.
  • Require reviewed update policy, protected publishing, and reproducible or independently attestable builds where supported.

Authoritative sources

Complete CVE record and remediation plan

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