During an Azure penetration test, an attacker identifies an Azure Function with an HTTP trigger that uses function-level keys. However, the function key was leaked in a public GitHub repository. What level of access does this key provide?
Function-level keys authorise invocation of only the specific function they belong to, not the whole Function App or subscription. A leaked key therefore permits unauthenticated calls to that single HTTP-triggered endpoint, matching the stem's scope.
Why this answer
Azure Function keys are per-function (or per-host) shared secrets used only to authorize HTTP invocations of that function's endpoint. A leaked function-level key lets an unauthenticated attacker call that specific function URL, but it does not grant Azure RBAC permissions, Key Vault access, or subscription-level control. The blast radius is limited to whatever the function itself does.
Exam trap
The trap is conflating a function-level shared secret with Azure AD/RBAC credentials — candidates overestimate the blast radius and pick subscription-wide or Key Vault options.
How to eliminate wrong answers
Option B is wrong because Key Vault secret decryption requires Azure AD authentication plus Key Vault access policies or RBAC roles — a function key is not an Azure AD token and cannot decrypt secrets. Option C is wrong because function keys do not grant SSH or worker-node access; the underlying App Service infrastructure is managed by Microsoft and not reachable via a function key. Option D is wrong because Owner-level subscription access requires Azure AD identity with an RBAC role assignment; function keys are scoped to the function app's HTTP endpoint only.