services / Azure / Web Apps Functions keys

Access keys for an individual Azure Functions function, used as bearer credentials to authorize HTTP invocation of that function.

Function invocation keys are credentials; invoking a function runs code under the function app's (possibly managed) identity. Asset is a single function app -> HIGH.

Microsoft.​Web/​Sites/​functions/​keys/​write

Sending a PUT request to set a function key lets an attacker set a known invocation credential (durable backdoor / persistence) enabling repeated invocation that runs code as the app's identity (lateral), and overwriting an existing key alters/revokes the legitimate credential (manipulation).

Risks

1. Data manipulation (HIGH)
2. Account persistence (BOOST)
3. Lateral movement (BOOST)

Scope: HIGH

This privilege may grant access to sensitive data from a single organizational function, or allow interruption of a service supporting a single organizational function.

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