Question 110
A cloud function accepts a caller-supplied URL and fetches an internal instance metadata endpoint, returning credentials. Which web weakness is the entry point?
Explanation
Correct Answer
The server performs a privileged fetch at an attacker-controlled destination inside its trusted network. Software vulnerabilities arise when untrusted data or a mutable object crosses an enforcement boundary without validation, isolation or correct sequencing. The case turns on a cloud function accepts a caller-supplied URL and fetches an internal instance metadata endpoint, returning credentials; “Server-side request forgery against a metadata service” addresses that precise condition. “An open redirect returning an attacker-chosen browser navigation URL” is not equivalent because a client redirect changes where the browser navigates; here the trusted server itself makes the privileged metadata fetch.
Incorrect Answers
A client redirect changes where the browser navigates; here the trusted server itself makes the privileged metadata fetch. Browser and web-origin mechanisms affect one request path; the right diagnosis depends on whether the client or trusted server is performing the sensitive action. In the reported situation, a cloud function accepts a caller-supplied URL and fetches an internal instance metadata endpoint, returning credentials. The effective mechanism is “Server-side request forgery against a metadata service”: the server performs a privileged fetch at an attacker-controlled destination inside its trusted network.
The exploit forces a server request, not code in another user's browser. The evidence is a cloud function accepts a caller-supplied URL and fetches an internal instance metadata endpoint, returning credentials. Browser and web-origin mechanisms affect one request path; the right diagnosis depends on whether the client or trusted server is performing the sensitive action. By contrast, “Server-side request forgery against a metadata service” operates on the specific concern: the server performs a privileged fetch at an attacker-controlled destination inside its trusted network.
CSRF can force browser-submitted actions, but the server-side URL fetch to a privileged internal destination is SSRF. Software vulnerabilities arise when untrusted data or a mutable object crosses an enforcement boundary without validation, isolation or correct sequencing. Here the decisive fact is a cloud function accepts a caller-supplied URL and fetches an internal instance metadata endpoint, returning credentials. “Server-side request forgery against a metadata service” matches that requirement because the server performs a privileged fetch at an attacker-controlled destination inside its trusted network.






CompTIA Security+ (SY0-701) Practice Tests