msgpack-numpy.yaml

rules:
  - id: msgpack-numpy
    message: >-
      Found usage of msgpack-numpy unpacking, which relies on pickle to deserialize numpy arrays containing objects.
      Functions reliant on pickle can result in arbitrary code execution. 
      Consider switching to a safer serialization method.
    languages: [python]
    severity: ERROR
    metadata:
      category: security
      cwe: "CWE-502: Deserialization of Untrusted Data"
      subcategory: [vuln]
      confidence: MEDIUM
      likelihood: MEDIUM
      impact: HIGH
      technology: [numpy]
      description: "Potential arbitrary code execution from functions reliant on pickling"
      references:
        - https://blog.trailofbits.com/2021/03/15/never-a-dill-moment-exploiting-machine-learning-pickle-files/

    pattern-either:
      - patterns:
          - pattern: msgpack.$FN(...)
          - metavariable-regex:
              metavariable: $FN
              regex: (loads?|dumps?|packb?|unpackb?)
          - pattern-inside: |
              msgpack_numpy.patch()
              ...

      - patterns:
          - pattern: msgpack.$FN(..., object_hook=msgpack_numpy.decode, ...)
          - metavariable-regex:
              metavariable: $FN
              regex: unpackb?

      - patterns:
          - pattern: msgpack.$FN(..., default=msgpack_numpy.encode, ...)
          - metavariable-regex:
              metavariable: $FN
              regex: packb?