Description
Express Gateway through 1.16.11 contains an authentication bypass vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the token secret or issuing client. Attackers with any valid client credentials and the identifier portion of another user's refresh token can obtain that user's access token and impersonate them against oauth2-protected APIs.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ExpressGateway | express-gateway | ≤ 1.16.11 | — |
References
- GitHub Issue #1076 issue-tracking
- https://github.com/ExpressGateway/express-gateway product
- https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/policies/oauth2/oauth2-server.js#L221-L247 technical-description
- https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/services/tokens/token.service.js#L100-L136 technical-description
- VulnCheck Advisory: Express Gateway through 1.16.11 OAuth 2.0 Refresh Token Validation Bypass third-party-advisory