azure-func-execute-as-via-code

Code modification on a Function app + the app runs as an MI => execute as that MI (via the identity endpoint).

derived azure emits CanExecuteAs

match

A conjunctive graph pattern. Variables (?x) bind node ids; every clause must hold.

where

optional

Present → upgrade the emitted state; absent → downgrade (not a hard requirement).

emit

source type	`Identity`
target type	`Identity`
source	`<principal>`
target	`<managed identity>`
permissions	`Microsoft.Web/sites/functions/write \| extensions/write \| sourcecontrols/Write`
state logic	if matched(optional[0]) or trigger_exists(?app): ACTIVE else: CONDITIONAL(trigger_exists)

source type

Identity

target type

Identity

source

<principal>

target

<managed identity>

permissions

Microsoft.Web/sites/functions/write | extensions/write | sourcecontrols/Write

state logic

if matched(optional[0]) or trigger_exists(?app): ACTIVE else: CONDITIONAL(trigger_exists)

Narrative

{principal.name} can overwrite code on {app.name} and, on trigger/invoke, mint the token of its identity {mi.name} from the App Service identity endpoint, executing as {mi.name}.

Raw rule rules/derived/azure/functions.yaml

id: azure-func-execute-as-via-code
emits: CanExecuteAs
description: Code modification on a Function app + the app runs as an MI => execute as that MI (via the
  identity endpoint).
match:
- - principal: null
  - CanModifyCode
  - app: null
- - app: null
  - ExecutesAs
  - mi: null
where:
- node_type(?app) in [ServerlessFunction, ApplicationPlatform]
- '?mi.privilege_level >= ?principal.privilege_level   # escalation only'
optional:
- - principal: null
  - CanInvoke
  - app: null
emit:
  source_type: Identity
  target_type: Identity
  source: <principal>
  target: <managed identity>
  state_logic: 'if matched(optional[0]) or trigger_exists(?app): ACTIVE

    else: CONDITIONAL(trigger_exists)

    '
  conditions_from:
  - app: null
  - mi: null
  permissions:
  - Microsoft.Web/sites/functions/write | extensions/write | sourcecontrols/Write
  derived_from:
  - <CanModifyCode edge_id>
  - <ExecutesAs edge_id>
  false_positive_note: Emit only when the app has a managed identity and that MI out-privileges the caller.
    No trigger and no CanInvoke -> CONDITIONAL(trigger_exists). Stopped app w/o CanStart -> CONDITIONAL(service_state).
  narrative: '{principal.name} can overwrite code on {app.name} and, on trigger/invoke, mint the token
    of its identity {mi.name} from the App Service identity endpoint, executing as {mi.name}.'