You found an SSRF, but the server only allows URLs from trusted.com. Game over? Not if trusted.com has an open redirect. Learn to chain a lowly redirect with SSRF to reach internal networks – and how PDF invoices can become your stealthy exfiltration channel.
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Welcome back. You’ve learned to confirm SSRF and bypass naive localhost blocks. Now we enter the big leagues: domain whitelists. The developer got smart — only URLs from *.target.com are allowed. Your external IPs and nip.io tricks are blocked. But every castle has a weak gate. If target.com itself has an open redirect vulnerability, that gate is wide open. This lesson will show you exactly how to chain an open redirect with SSRF, plus a bonus scenario: exploiting SSRF through a PDF invoice generator where your profile HTML becomes the attack vector.
The Whitelist Wall: When Only One Domain Is Allowed
Imagine an SSRF endpoint with a strict whitelist:https://target.com/proxy?url=https://api.target.com/fetch