Elasticsearch field disclosure flaw (ESA-2021-05)
A document disclosure flaw was found in Elasticsearch when Document or Field Level Security is used. Get requests do not properly apply security permissions when executing a query against a recently updated document. This affects documents that have been updated and not yet refreshed in the index. This could result in the search disclosing the existence of documents and fields the attacker should not be able to view. A mitigating factor to this flaw is an attacker must know the document ID to run the get request.
All versions of Elasticsearch after 7.6.0 and before 7.11.0 are affected by this flaw
Solutions and Mitigations:
Anyone using Document or Field Level Security should upgrade to Elasticsearch version 7.11.0. There is no known workaround for this flaw.
CVSSv3 - 2.6: AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CVE ID: CVE-2021-22134