EncryptCodec
Simulations/Open Redirect

Open Redirect

Beginner

Open redirects let attackers craft links that appear to come from a trusted domain but redirect victims to malicious sites. Exploit the vulnerability, bypass a naive fix, then implement proper validation.

Progress:
1
Basic Open Redirect
2
Bypass Domain Check
3
Apply Strict Validation
Security Level:
app.example.com/login?redirect=...

Login

Redirect Flow
1
Attacker sends link
app.example.com/login?redirect=...
2
Victim logs in
Credentials sent to legitimate server
3
Server redirects (no check)
302 Location: ...
4
Victim lands safely
...

Challenges

1
Basic Open Redirect
Craft a redirect URL that sends the user to an attacker-controlled site after login.
▼ hints
2
Bypass Domain Check
The developer added a basic check that the URL contains 'example.com'. Bypass it.
▼ hints
3
Apply Strict Validation
Switch to strict domain validation and verify that the bypass no longer works.
▼ hints
How to fix open redirects
Whitelist allowed domains and use proper URL parsing
▼

Frequently Asked Questions