## Summary
OpenSearch SQL plugin contains a SQL query validation bypass in the Flint extension query handler. A remote authenticated user with async query access can bypass the SQL grammar deny list via the direct query endpoint and achieve arbitrary code execution on Apache Spark workers.
## Technical Details
- Root issue: the Flint extension query handler validates SQL queries without sufficient restrictions, enabling a bypass of the SQL grammar deny list.
- Exploit path: submit a crafted SQL query to the direct query endpoint that embeds prohibited SQL constructs within materialized view creation statements.
- Result: the crafted statement can cause arbitrary code execution on Apache Spark workers.
- Affected component: OpenSearch SQL plugin “Flint extension query handler” and its direct query integration with external data sources via Apache Spark.
## Affected
- OpenSearch SQL plugin (open-source, self-managed): v2.13 to v3.6
- Amazon OpenSearch Service (managed): v2.13 to v3.5
- Fixed versions:
- OpenSearch SQL plugin: 2.19.6 and 3.7.0 (also referenced as 3.7 and 2.19.6)
- Amazon OpenSearch Service: fixed via service software update in all affected versions 2.13 to 3.5
## Impact
- Preconditions:
- Remote authenticated access
- Async query access
- Direct query feature configured (external data sources with Spark integration)
- Impact scope: confidentiality, integrity, and availability impact on Spark workers via arbitrary code execution.
## Mitigation
1. Upgrade OpenSearch SQL plugin to 2.19.6 or 3.7.0 (or the corresponding 3.7/2.19.6 fixes referenced by the advisory).
2. For Amazon OpenSearch Service, update the domain to the latest service software version (no engine upgrade required) and apply the update from the console as described by AWS.
3. Until patched, restrict async query access to trusted users only, especially for clusters using the direct query feature.
4. Ensure any forked/derivative code incorporates the upstream fixes.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-693