Vulnerability in express-jwt (CVE-2020-15084)
Summary
Vulnerability in express-jwt (CVE-2020-15084). Confidential information can be exposed externally. Mitigation: upgrade to 6.0.0 or later.
Original description
The description as published by the source.
Overview
Versions before and including 5.3.3, we are not enforcing the algorithms entry to be specified in the configuration.
When algorithms is not specified in the configuration, with the combination of jwks-rsa, it may lead to authorization bypass.
Am I affected?
You are affected by this vulnerability if all of the following conditions apply:
You are using express-jwt
AND
You do not have algorithms configured in your express-jwt configuration.
AND
You are using libraries such as jwks-rsa as the secret.
How to fix that?
Specify algorithms in the express-jwt configuration. The following is an example of a proper configuration
const checkJwt = jwt({
secret: jwksRsa.expressJwtSecret({
rateLimit: true,
jwksRequestsPerMinute: 5,
jwksUri: `https://${DOMAIN}/.well-known/jwks.json`
}),
// Validate the audience and the issuer.
audience: process.env.AUDIENCE,
issuer: `https://${DOMAIN}/`,
// restrict allowed algorithms
algorithms: ['RS256']
});
Will this update impact my users?
The fix provided in patch will not affect your users if you specified the algorithms allowed. The patch now makes algorithms a required configuration.
Credit
IST Group
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-15084 has been found in express-jwt.
Confidential information can be exposed externally.
What to do: upgrade express-jwt to 6.0.0 or later.
If unsure, ask your IT team or search "express-jwt CVE-2020-15084" on the vendor's site.
CVE-2020-15084 (express-jwt) — CWE-285
Attack vector: remote (network-reachable)
Patched: 6.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-285) exists in express-jwt.
Check the vendor advisory for the affected versions of express-jwt.
Severity: ?. Confidential information can be exposed externally.
Update to 6.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'express-jwt' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'express-jwt' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
express-jwtを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade express-jwt to 6.0.0ステージング環境で 6.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- web github.com
- web github.com