Auth0.jsApplication · Auth0

CVE-2018-6873

CRITICAL · 9.8 CVSS v3.0 Published 2018-04-04
Fix available
A fix is available. Upgrade to after 8.10.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Auth0 authentication service before 2017-10-15 allows privilege escalation because the JWT audience is not validated.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Auth0 authentication service before October 15, 2017 did not validate the JWT audience ('aud' claim, allowing attackers to craft tokens with manipulated audience values and achieve privilege escalation. The missing validation means any JWT with a valid signature but wrong audience could be accepted.

MitigationUpdate Auth0 libraries/SDKs to versions released after 2017-10-15 that enforce audience validation, or explicitly implement 'aud' claim verification in JWT validation logic to ensure it matches the expected audience identifier.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Auth0.jsApplication
Affected:<= 8.10.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Auth0.js version in use
    Inspect your package.json file, node_modules/auth0-js/package.json, or the bundled script version. Look for the 'version' field in the auth0-js dependency.
    Affected if The installed Auth0.js version is 8.10.1 or earlier (any version <= 8.10.1).
  2. Verify JWT validation includes audience claim check
    Review your application's JWT validation code that processes Auth0 tokens. Search for code that validates the 'aud' claim in the decoded JWT payload.
    Affected if The JWT validation logic does not explicitly verify that the 'aud' claim matches your expected audience identifier, or no audience validation exists.
  3. Confirm library update timeline
    Check the last update date of your Auth0.js dependency. Review your dependency management system or lock files for update timestamps.
    Affected if The Auth0.js library has not been updated since before October 15, 2017, and remains at a vulnerable version.

You are affected if your deployed Auth0.js version is 8.10.1 or earlier AND your JWT validation does not perform explicit 'aud' claim verification.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 8.10.1
Interim mitigation

Update Auth0 libraries/SDKs to versions released after 2017-10-15 that enforce audience validation, or explicitly implement 'aud' claim verification in JWT validation logic to ensure it matches the expected audience identifier.

Recommended fix Moderate confidence

auth0-js version 8.12.0 or later (specifically any version released after October 2017)

  1. 1. Check the current version of auth0.js in your project by examining package.json or running npm list auth0-js
  2. 2. Identify all locations where auth0.js is used (client-side applications, CDNs, dependencies)
  3. 3. Update the auth0.js dependency to version 8.12.0 or later by running: npm install auth0-js@^8.12.0
  4. 4. Verify the upgrade by running npm list auth0-js to confirm the new version
  5. 5. Test authentication flows to ensure the JWT audience validation is working correctly
  6. 6. If using a package manager like yarn, run yarn upgrade auth0-js to update
  7. 7. Rebuild and redeploy any applications that bundle auth0.js
Caveat Low risk - this is a patch upgrade within the same major version. Verify that any custom authentication callbacks still function correctly after the upgrade.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Auth0.js Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-6873 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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