CVE intelligence and bounded remediation

CVE-2020-15084 — Auth0 Express-Jwt security vulnerability

Critical CVSS 9.1

In express-jwt (NPM package) up and including version 5.3.3, the algorithms entry to be specified in the configuration is not being enforced. When algorithms is not specified in the configuration, with the combination of jwks-rsa, it may lead to authorization bypass. You are affected by this vulnerability if all of the following conditions apply: - You are using express-jwt - You do not have **algorithms** configured in your express-jwt configuration. - You are using libraries such as jwks-rsa as the **secret**. You can fix this by specifying **algorithms** in the express-jwt configuration. See linked GHSA for example. This is also fixed in version 6.0.0.

Severity
Critical
CVSS
9.1 (3.1)
Published
2020-06-30
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-285, CWE-863

Affected products

  • auth0 / express-jwt

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

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Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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