Server-Side Request Forgery (SSRF)

SSRF occurs when an attacker can cause a server to make requests to unintended locations. This can be used to access internal services, scan internal networks, and exfiltrate data.

Attack Scenarios

• Accessing internal APIs (e.g., cloud metadata endpoints)
• Scanning internal network ports
• Reading local files via file:// protocol
• Bypassing firewalls and access controls

Prevention

• Validate and sanitize all URLs before making server-side requests
• Use allowlists of permitted domains and IP ranges
• Block requests to private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
• Block cloud metadata endpoints (169.254.169.254)
• Implement network segmentation