OWASP SSRF Prevention Cheat Sheet

1. Context

   What SSRF is and why it matters.

2. SSRF Common Flow

   Typical attack sequence and impact.

3. Case 1 Trusted Destinations

   Allow-listing known destinations and avoiding user-controlled URLs.

4. Case 2 Arbitrary Destinations

   Validating IPs and DNS, blocking internal ranges and redirects.

5. IMDSv2 in AWS

   Protecting cloud instance metadata from SSRF.

6. Deny-List Last Resort

   Limitations of block lists for SSRF.

7. Webhook Security

   Safe webhook delivery and receiving including SSRF concerns.

8. Network Segmentation

   Egress filtering and segmentation limiting SSRF reach.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.