Описание
client-certificate-auth Vulnerable to Open Redirect via Host Header Injection in HTTP-to-HTTPS redirect
Summary
Versions 0.2.1 and 0.3.0 of client-certificate-auth contain an open redirect vulnerability. The middleware unconditionally redirects HTTP requests to HTTPS using the unvalidated Host header, allowing an attacker to redirect users to arbitrary domains.
Vulnerable Code
Attack Scenario
- Attacker crafts a link:
http://vulnerable-app.example.com/login - When victim clicks, attacker intercepts and injects header:
Host: attacker.com - Server responds:
302 Found → https://attacker.com/login - Victim is redirected to attacker-controlled site
Impact
- Phishing: Attackers can use trusted domain links to redirect victims to credential-harvesting pages
- OAuth/SSO Token Theft: In authentication flows, authorization codes or tokens may leak via redirect
- Referer Leakage: Sensitive URL parameters may be exposed to attacker domains via the Referer header
- Cache Poisoning: In deployments with shared caches, malicious redirects may be cached and served to other users
Exploitability
Exploitation requires that HTTP traffic reaches the Node.js application without TLS termination setting x-forwarded-proto: https. This condition is uncommon in production deployments behind modern reverse proxies or load balancers, which limits real-world exploitability.
Fix
The vulnerable redirect behavior has been completely removed in version 1.0.0.
Workarounds
If upgrading is not immediately possible:
- Block HTTP traffic at the network/load balancer level
- Ensure your reverse proxy always sets
x-forwarded-proto: https - Add middleware before
clientCertificateAuthto validate theHostheader against an allowlist
References
Ссылки
Пакеты
client-certificate-auth
>= 0.2.1, < 1.0.0
1.0.0