Executive brief
Warpgate is an open source bastion host that provides centralized access control for SSH, HTTPS, and MySQL connections. An attacker can craft a malicious login URL that, when clicked by a victim who completes single sign-on, executes JavaScript in the authenticated Warpgate session or redirects to an attacker-controlled site. This allows attackers to steal session credentials, impersonate users, or perform unauthorized administrative actions.
Technical details
The vulnerability is a stored cross-site scripting (XSS) and open redirect flaw in the SSO endpoints. The /@warpgate/api/sso/providers/:name/start endpoint stores an attacker-controlled "next" parameter, which is later inserted without HTML escaping into responses generated by the SSO return handler in warpgate-protocol-http/src/api/sso_provider_list.rs. An unauthenticated attacker can craft a link containing malicious JavaScript, and when an authenticated user follows it, the code executes in their browser with access to user and (if applicable) administrator APIs.
Affected products
- Warp Tech Warpgate before 0.25.5
Timeline
- 2026-09-21: disclosed
- 2026-06-18: patched: Version 0.25.5 released with HTML escaping fix