GHSA-v3cg-7r9h-r2g6

### Advisory title: Field-level security issue with .keyword fields ### Affected versions: OpenSearch 1.0.0-1.3.7 and 2.0.0-2.4.1 ### Patched versions: OpenSearch 1.3.8 and 2.5.0 ### Impact: There is an issue in the implementation of field-level security (FLS) and field masking where rules written to explicitly exclude fields are not correctly applied for certain queries that rely on their auto-generated .keyword fields. This issue is only present for authenticated users with read access to the indexes containing the restricted fields. ### Workaround: FLS rules that use explicit exclusions can be written to grant explicit access instead. Policies authored in this way are not subject to this issue. ### Patches: OpenSearch versions 1.3.8 and 2.5.0 contain a fix for this issue. ### For more information: If you have any questions or comments about this advisory, please contact AWS/Amazon Security via our issue reporting page (https://aws.amazon.com/security/vulnerability-reporting/) or directly via email to [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.