Security Limitations

Plugins

Elasticsearch’s plugin infrastructure is extremely flexible in terms of what can be extended. While it opens up Elasticsearch to a wide variety of (often custom) additional functionality, when it comes to security, this high extensibility level comes at a cost. We have no control over the third-party plugins' code (open source or not) and therefore we cannot guarantee their compliance with X-Pack security. For this reason, third-party plugins are not officially supported on clusters with X-Pack security enabled.

Changes in Index Wildcard Behavior

Elasticsearch clusters with X-Pack security enabled apply the /_all wildcard, and all other wildcards, to the indices that the current user has privileges for, not the set of all indices on the cluster. While creating or retrieving aliases by providing wildcard expressions for alias names, if there are no existing authorized aliases that match the wildcard expression provided an IndexNotFoundException is returned.

Multi Document APIs

Multi get and multi term vectors API throw IndexNotFoundException when trying to access non existing indices that the user is not authorized for. By doing that they leak information regarding the fact that the index doesn’t exist, while the user is not authorized to know anything about those indices.

Filtered Index Aliases

Aliases containing filters are not a secure way to restrict access to individual documents, due to the limitations described in Index and Field Names Can Be Leaked When Using Aliases. X-Pack security provides a secure way to restrict access to documents through the document-level security feature.

Field and Document Level Security Limitations

When a user’s role enables document or field level security for an index:

  • The user cannot perform write operations:

    • The update API isn’t supported.
    • Update requests included in bulk requests aren’t supported.
  • The request cache is disabled for search requests.

When a user’s role enables document level security for an index:

  • Document level security isn’t applied for APIs that aren’t document based. An example is the field stats API.
  • Document level security doesn’t affect global index statistics that relevancy scoring uses. So this means that scores are computed without taking the role query into account. Note that documents not matching with the role query are never returned.
  • The has_child and has_parent queries aren’t supported as query in the role definition. The has_child and has_parent queries can be used in the search API with document level security enabled.
  • Any query that makes remote calls to fetch data to query by isn’t supported. The following queries aren’t supported:

    • The terms query with terms lookup isn’t supported.
    • The geo_shape query with indexed shapes isn’t supported.
    • The percolate query isn’t supported.

Index and Field Names Can Be Leaked When Using Aliases

Calling certain Elasticsearch APIs on an alias can potentially leak information about indices that the user isn’t authorized to access. For example, when you get the mappings for an alias with the _mapping API, the response includes the index name and mappings for each index that the alias applies to. Similarly, the response to a _field_stats request includes the name of the underlying index, rather than the alias name.

Until this limitation is addressed, avoid index and field names that contain confidential or sensitive information.

LDAP Realm

The LDAP Realm does not currently support the discovery of nested LDAP Groups. For example, if a user is a member of group_1 and group_1 is a member of group_2, only group_1 will be discovered. However, the Active Directory Realm does support transitive group membership.