The Keys to the Kingdom: Understanding SSRF and Cloud Metadata Services
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"Access Denied," the firewall effectively said. "Nice try." The Keys to the Kingdom: Understanding SSRF and
If you are not running on GCE (e.g., on-premise, AWS, or local dev), you cannot use the metadata server. Instead: or local dev)
The URL metadata.google.internal is a special internal DNS name accessible only from within a GCP Compute Engine instance. It is not reachable from the public internet. When a developer needs a script to perform an action (like uploading a file to a bucket), the script queries this local URL to get an OAuth 2.0 access token. This eliminates the need to hardcode sensitive credentials directly into the application code. 2. The Vulnerability: Server-Side Request Forgery (SSRF) The Keys to the Kingdom: Understanding SSRF and