Cassandra JavaScript UDF Creation

Last updated 3 days ago on 2026-07-30

Created 3 days ago on 2026-07-30

About

Identifies Cassandra Query Language statements that create a JavaScript user-defined function. On vulnerable and dangerously configured Cassandra servers, adversaries can abuse scripted UDF creation to escape the JavaScript sandbox and execute operating-system commands, including through CVE-2021-44521.

Tags

Domain: NetworkUse Case: Network Security MonitoringUse Case: Threat DetectionUse Case: VulnerabilityTactic: ExecutionData Source: Network Packet CaptureLanguage: eql

Severity

high

Risk Score

MITRE ATT&CK™

Execution (TA0002)(external, opens in a new tab or window)

↳ Command and Scripting Interpreter (T1059)(external, opens in a new tab or window)

False Positive Examples

Developers or database administrators may deploy approved JavaScript UDFs in environments where scripted functions are intentionally enabled. Validate the function body, client address, Cassandra version, configuration, and change window before escalating.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-network_traffic.cassandra-*
Related Integrations: network_traffic(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗any where data_stream.dataset == "network_traffic.cassandra" and
    network_traffic.cassandra.request.query like~ "*create*function*" and
    network_traffic.cassandra.request.query like~ "*language*javascript*"

Install detection rules in Elastic Security

Detect Cassandra JavaScript UDF Creation in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).