Fetch-url-http-3a-2f-2fmetadata.google.internal-2fcomputemetadata-2fv1-2finstance-2fservice Accounts-2f Upd ✰

The string fetch-url-http-3A-2F-2Fmetadata.google.internal-2FcomputeMetadata-2Fv1-2Finstance-2Fservice accounts-2F is an URL-encoded representation of a direct API request to a Google Cloud virtual environment.

This returns a JSON access token you can use in Authorization headers when calling Google APIs:

# Set the endpoint variable TOKEN_URL="http://google.internal" # Fetch the token using curl curl -H "Metadata-Flavor: Google" $TOKEN_URL Use code with caution. The Output The server returns a JSON object containing: The string fetch-url-http-3A-2F-2Fmetadata

curl -H "Metadata-Flavor: Google" \ "http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token"

The string traveled deeper, navigating the hierarchy of the cloud instance: It reached the API. It stepped into the instance details. It knocked on the door of the service-accounts . It stepped into the instance details

Response (JSON):

Google requires a specific HTTP header to protect against Server-Side Request Forgery (SSRF) attacks. If a request hits this URL without the header, the server rejects it. If a request hits this URL without the

: This URL is only reachable from within a Google Cloud resource; it is not accessible over the public internet.

Specifically, the decoded endpoint is:

When an application or logging system records an action, it often sanitizes or URL-encodes special characters. Breaking down the specific parts of this signature helps explain what an attacker or an internal automated process is attempting to do: Introduction to service identity | Cloud Run

Example token response (JSON):