Potential Server Side Template Injection In Velocity — Sigma Rule

Rule metadata and linked tags

Author: Moti Harmats. Source status: test; severity: high. Source dates: 2023-02-11 / not supplied.

{
  "category": "application",
  "product": "velocity",
  "definition": "Requirements: application error logs must be collected (with LOG_LEVEL=ERROR and above)"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 859dd6dcb4a12802a1224afa14711ed97bb625a999bc4bd61ad2b7e5b14bd8bf

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential Server Side Template Injection In Velocity
id: 16c86189-b556-4ee8-b4c7-7e350a195a4f
status: test
description: Detects exceptions in velocity template renderer, this most likely happens due to dynamic rendering of user input and may lead to RCE.
references:
    - https://antgarsil.github.io/posts/velocity/
    - https://www.wix.engineering/post/threat-and-vulnerability-hunting-with-application-server-error-logs
author: Moti Harmats
date: 2023-02-11
tags:
    - attack.initial-access
    - attack.t1190
logsource:
    category: application
    product: velocity
    definition: 'Requirements: application error logs must be collected (with LOG_LEVEL=ERROR and above)'
detection:
    keywords:
        - 'ParseErrorException'
        - 'VelocityException'
        - 'TemplateInitException'
    condition: keywords
falsepositives:
    - Application bugs
    - Missing .vm files
level: high

Original YAML and metadata in JSON

False positives

• Application bugs
• Missing .vm files

Source references

• https://antgarsil.github.io/posts/velocity/
• https://www.wix.engineering/post/threat-and-vulnerability-hunting-with-application-server-error-logs