An issue was identified that allowed the unsafe deserialization of java objects from hadoop or spark configuration properties that could have been modified by authenticated users. Elastic would like to thank Yakov Shafranovich, with Amazon Web Services for reporting this issue.

An issue has been identified with how Elasticsearch handled incoming requests on the HTTP layer. An unauthenticated user could force an Elasticsearch node to exit with an OutOfMemory error by sending a moderate number of malformed HTTP requests. The issue was identified by Elastic Engineering and we have no indication that the issue is known or that it is being exploited in the wild.

In Elasticsearch versions before 7.13.3 and 6.8.17 an uncontrolled recursion vulnerability that could lead to a denial of service attack was identified in the Elasticsearch Grok parser. A user with the ability to submit arbitrary queries to Elasticsearch could create a malicious Grok query that will crash the Elasticsearch node.

In Elasticsearch versions before 7.11.2 and 6.8.15 a document disclosure flaw was found when Document or Field Level Security is used. Search queries do not properly preserve security permissions when executing certain cross-cluster search queries. This could result in the search disclosing the existence of documents the attacker should not be able to view. This could result in an attacker gaining additional insight into potentially sensitive indices.

Elasticsearch versions before 7.11.2 and 6.8.15 contain a document disclosure flaw was found in the Elasticsearch suggester and profile API when Document and Field Level Security are enabled. The suggester and profile API are normally disabled for an index when document level security is enabled on the index. Certain queries are able to enable the profiler and suggester which could lead to disclosing the existence of documents and fields the attacker should not be able to view.

Elasticsearch versions before 7.10.0 and 6.8.14 have an information disclosure issue when audit logging and the emit_request_body option is enabled. The Elasticsearch audit log could contain sensitive information such as password hashes or authentication tokens. This could allow an Elasticsearch administrator to view these details.

Elasticsearch versions before 6.8.13 and 7.9.2 contain a document disclosure flaw when Document or Field Level Security is used. Search queries do not properly preserve security permissions when executing certain complex queries. This could result in the search disclosing the existence of documents the attacker should not be able to view. This could result in an attacker gaining additional insight into potentially sensitive indices.

In Elasticsearch before 7.9.0 and 6.8.12 a field disclosure flaw was found when running a scrolling search with Field Level Security. If a user runs the same query another more privileged user recently ran, the scrolling search can leak fields that should be hidden. This could result in an attacker gaining additional permissions against a restricted index.

A race condition flaw was found in the response headers Elasticsearch versions before 7.2.1 and 6.8.2 returns to a request. On a system with multiple users submitting requests, it could be possible for an attacker to gain access to response header containing sensitive data from another user.

A permission issue was found in Elasticsearch versions before 5.6.15 and 6.6.1 when Field Level Security and Document Level Security are disabled and the _aliases, _shrink, or _split endpoints are used . If the elasticsearch.yml file has xpack.security.dls_fls.enabled set to false, certain permission checks are skipped when users perform one of the actions mentioned above, to make existing data available under a new index/alias name. This could result in an attacker gaining additional permissions against a restricted index.

Elasticsearch Security versions 6.5.0 and 6.5.1 contain an XXE flaw in Machine Learning's find_file_structure API. If a policy allowing external network access has been added to Elasticsearch's Java Security Manager then an attacker could send a specially crafted request capable of leaking content of local files on the Elasticsearch node. This could allow a user to access information that they should not have access to.