Cassandra JavaScript UDF Creation
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…
Description
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.
Detection logic
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- event_index
Known benign triggers
- 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.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| attack.mitre.org/techniques/T1059/007/ | 2from 2 sources |
| jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution/ | Only this detection cites it |
| nvd.nist.gov/vuln/detail/CVE-2021-44521 | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- b3e2c2ad-9a81-4638-bf12-7ca2feed66a2
- Tagged by the source as
- Data Source: Network Packet CaptureDomain: NetworkNoise: UnknownPerformance: FastProfile: RecommendedResources: Investigation GuideRule Type: Event Correlation (EQL)Tactic: ExecutionThreat: Vulnerability ExploitUse Case: Network Security MonitoringUse Case: Threat DetectionUse Case: VulnerabilityVuln: CVE-2021-44521
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3