gcp-appengine-execute-as-deploy

Deploy a new App Engine version (attacker code) that executes as the runtime SA.

derived gcp emits CanExecuteAs

match

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

{'principal': None} CanModifyCode {'app': None} {'instance': None} ExecutesAs {'sa': None}

where

?instance belongs to a version of ?app (or a new version the principal creates on ?app) ?sa.privilege_level >= ?principal.privilege_level # escalation only

optional

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

{'principal': None} CanModifyConfiguration {'app': None}

emit

source typeIdentity
target typeIdentity
source<principal>
target<runtime service account>
permissionsappengine.versions.create
state logicif matched(optional[0]) or new version auto-serves or trigger_exists(?app): ACTIVE else: CONDITIONAL(trigger_exists) # deployed but not receiving traffic yet

Narrative

{principal.name} can deploy an App Engine version (appengine.versions.create) that runs as {sa.name}, executing attacker code with that SA's permissions.

Raw rule rules/derived/gcp/appengine.yaml

id: gcp-appengine-execute-as-deploy
emits: CanExecuteAs
description: Deploy a new App Engine version (attacker code) that executes as the runtime SA.
match:
- - principal: null
  - CanModifyCode
  - app: null
- - instance: null
  - ExecutesAs
  - sa: null
where:
- ?instance belongs to a version of ?app (or a new version the principal creates on ?app)
- '?sa.privilege_level >= ?principal.privilege_level   # escalation only'
optional:
- - principal: null
  - CanModifyConfiguration
  - app: null
emit:
  source_type: Identity
  target_type: Identity
  source: <principal>
  target: <runtime service account>
  permissions:
  - appengine.versions.create
  state_logic: 'if matched(optional[0]) or new version auto-serves or trigger_exists(?app): ACTIVE else:
    CONDITIONAL(trigger_exists)   # deployed but not receiving traffic yet

    '
  conditions_from:
  - app: null
  - sa: null
  confidence: min(contributing) * 0.95
  derived_from:
  - <CanModifyCode edge_id>
  - <ExecutesAs edge_id>
  false_positive_note: 'Escalation strength depends on the runtime SA''s ACTUAL roles (Editor not guaranteed).
    If deploy is CONDITIONAL on build/storage perms, propagate that condition.

    '
  narrative: '{principal.name} can deploy an App Engine version (appengine.versions.create) that runs
    as {sa.name}, executing attacker code with that SA''s permissions.'
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