A vulnerability in keras-team/keras version 3.14.0 allows for arbitrary code execution due to improper handling of deserialization in the Lambda layer. Specifically, the _raise_for_lambda_deserialization() function fails to enforce the safe-mode guard when safe_mode is set to None, which is the default value when from_config() is called outside of a SafeModeScope context. This logic error conflates None (unset/default-deny) with False (explicitly disabled), bypassing the guard and allowing attacker-controlled marshal bytecode to be deserialized. Affected call sites include keras.layers.deserialize(config), keras.models.clone_model(model), and any direct invocation of Lambda.from_config(config) without an enclosing SafeModeScope(True). This vulnerability can be exploited to achieve arbitrary OS-level code execution in the context of the server or user process.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Keras | Keras | 3.14.0 (including) | 3.14.0 (including) |
Potential Mitigations
- Make fields transient to protect them from deserialization.
- An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.