Описание
SpiceDB: Checks involving relations with caveats can result in unconditional permission when conditional permission is expected
Impact
Under concurrency, CheckPermission and CheckBulkPermissions can return PERMISSIONSHIP_HAS_PERMISSION for a (resource, permission, subject) whose correct answer is PERMISSIONSHIP_CONDITIONAL_PERMISSION.
You are impacted if all of the following hold:
- Your schema has a permission combining relations with an intersection or exclusion, where a subject reaches it through a caveated branch and a non-caveated branch. For example:
- A subject reaches the permission via the caveated edge:
- Your workload issues
LookupResourceswith acontextrequest parameter, concurrently withCheckPermission/CheckBulkPermissionsfor the same subject/resource, and - The dispatch result cache is enabled.
When all of the above are true, there is an intermittent window in which:
CheckPermission(document:firstdoc, has_permission, user:caveatedreader) → HAS_PERMISSION (incorrect; should be CONDITIONAL_PERMISSION)
CheckPermission(document:firstdoc, has_permission, user:caveatedreader, context = {"somecondition": 41}) → HAS_PERMISSION (incorrect; should be NO_PERMISSION)
Patches
v1.54.0
Workarounds
Disable the dispatch result cache (ClusterDispatchCacheConfig and DispatchCacheConfig)
Пакеты
github.com/authzed/spicedb
>= 1.34.0, < 1.54.0
1.54.0
Связанные уязвимости
SpiceDB is an open source database system for creating and managing security-critical application permissions. From 1.34.0 until 1.54.0, SpiceDB can return PERMISSIONSHIP_HAS_PERMISSION instead of PERMISSIONSHIP_CONDITIONAL_PERMISSION or PERMISSIONSHIP_NO_PERMISSION because checkRequestToKey() and checkRequestToKeyWithCanonical() in internal/dispatch/keys/computed.go omit CheckHints when constructing dispatch Check cache keys. The incorrect result requires a permission combining relations with intersection or exclusion, a subject reachable through caveated and non-caveated branches, LookupResources with a context parameter running concurrently with CheckPermission or CheckBulkPermissions for the same resource and subject, and an enabled dispatch result cache. Under these conditions, a result computed for one hint set can poison the cache entry used by a semantically different authorization check, allowing permission without satisfying the caveat. This issue is fixed in version 1.54.0.