azure-containerapps-execute-as-via-write

Control-plane image/command replacement + 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.

{'principal': None} CanModifyCode {'app': None} {'app': None} ExecutesAs {'mi': None}

where

node_type(?app) in [ContainerService, BatchJob] ?mi.privilege_level > ?principal.privilege_level # strict escalation only (equal-privilege lateral excluded) ?mi is reachable from the main container (identitySettings.lifecycle in [All, Main] or unset)

emit

source typeIdentity
target typeIdentity
source<principal>
target<managed identity>
permissionsMicrosoft.App/containerApps/write

Narrative

{principal.name} can replace the image/command of {app.name} (containerApps/write) and mint the token of its identity {mi.name} from the local identity endpoint, executing as {mi.name}.

Raw rule rules/derived/azure/containerapps.yaml

id: azure-containerapps-execute-as-via-write
emits: CanExecuteAs
description: Control-plane image/command replacement + 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 [ContainerService, BatchJob]
- '?mi.privilege_level > ?principal.privilege_level   # strict escalation only (equal-privilege lateral
  excluded)'
- ?mi is reachable from the main container (identitySettings.lifecycle in [All, Main] or unset)
emit:
  source_type: Identity
  target_type: Identity
  source: <principal>
  target: <managed identity>
  conditions_from:
  - app: null
  - mi: null
  permissions:
  - Microsoft.App/containerApps/write
  derived_from:
  - <CanModifyCode edge_id>
  - <ExecutesAs edge_id>
  false_positive_note: Emit only when the app has an MI reachable from the main container and that MI
    out-privileges the caller. containerApps/write alone (no exec) is sufficient because the new revision
    runs attacker code.
  narrative: '{principal.name} can replace the image/command of {app.name} (containerApps/write) and mint
    the token of its identity {mi.name} from the local identity endpoint, executing as {mi.name}.'
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