Code injection in `saved_model_cli`

Impact

TensorFlow's saved_model_cli tool is vulnerable to a code injection as it calls eval on user supplied strings

def preprocess_input_exprs_arg_string(input_exprs_str):
  ... 
  for input_raw in filter(bool, input_exprs_str.split(';')):
    ...
    input_key, expr = input_raw.split('=', 1)
    input_dict[input_key] = eval(expr)
  ...

This can be used by attackers to run arbitrary code on the plaform where the CLI tool runs.
However, given that the tool is always run manually, the impact of this is not severe. We have patched this by adding a safe flag which defaults to True and an explicit warning for users.

Patches

We have patched the issue in GitHub commit 8b202f08d52e8206af2bdb2112a62fafbc546ec7.

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported by Omer Kaspi from Vdoo.