CVE intelligence and bounded remediation

CVE-2021-27884 — Weak JSON Web Token (JWT) signing secret generation in YMFE YApi through 1.9.2 allows recreation of other users' JWT tokens

Medium CVSS 5.1

Weak JSON Web Token (JWT) signing secret generation in YMFE YApi through 1.9.2 allows recreation of other users' JWT tokens. This occurs because Math.random in Node.js is used.

Severity
Medium
CVSS
5.1 (3.1)
Published
2021-03-01
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-330

Affected products

  • ymfe / yapi

Matched remediation archetype

Cryptography, certificate, signature, and channel validation

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

Check exposure

  • Inventory affected algorithms, key uses, trust stores, certificate validation settings, random sources, and plaintext channels across clients and services.
  • Determine which secrets, identities, signatures, or data protections depend on the affected primitive or validation path.
  • Check debug, compatibility, fallback, and hostname or audience override settings in build and runtime configuration.

Remediate safely

  • Use a maintained platform cryptographic API with approved algorithms, modes, parameters, randomness, and full peer identity validation.
  • Remove insecure fallback and validation bypasses; separate keys by purpose and load them from managed secret storage.
  • Plan rotation or reissuance for affected keys, certificates, tokens, hashes, or ciphertext and document compatibility sequencing.

Authoritative sources

Complete CVE record and remediation plan

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