Server Side Template Injection Strings — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-06-14 / not supplied.

{
  "category": "webserver"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 44d968cd9205bb30f04ada63c54cf4c01a69f1f69a4e60fcdcf7aca305be2054

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: Server Side Template Injection Strings
id: ada3bc4f-f0fd-42b9-ba91-e105e8af7342
status: test
description: Detects SSTI attempts sent via GET requests in access logs
references:
    - https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection
    - https://github.com/payloadbox/ssti-payloads
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-14
tags:
    - attack.stealth
    - attack.t1221
logsource:
    category: webserver
detection:
    select_method:
        cs-method: 'GET'
    keywords:
        - '={{'
        - '=%7B%7B'
        - '=${'
        - '=$%7B'
        - '=<%='
        - '=%3C%25='
        - '=@('
        - 'freemarker.template.utility.Execute'
        - .getClass().forName('javax.script.ScriptEngineManager')
        - 'T(org.apache.commons.io.IOUtils)'
    filter:
        sc-status: 404
    condition: select_method and keywords and not filter
falsepositives:
    - User searches in search boxes of the respective website
    - Internal vulnerability scanners can cause some serious FPs when used, if you experience a lot of FPs due to this think of adding more filters such as "User Agent" strings and more response codes
level: high

Original YAML and metadata in JSON

False positives

• User searches in search boxes of the respective website
• Internal vulnerability scanners can cause some serious FPs when used, if you experience a lot of FPs due to this think of adding more filters such as "User Agent" strings and more response codes

Source references

• https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection
• https://github.com/payloadbox/ssti-payloads