CVE-2020-15084: Security Update for express-jwt Library
Published: June 30, 2020
CVE number: CVE-2020-15084
Credit: IST Group
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 or potentially other asymmetric crypto libraries, 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']
});
Was this helpful?
Will this update impact my users?
The fix provided in the patch will not affect your users if you specified the algorithms allowed. The patch now makes algorithms a required configuration.