Patched code sample

The specified CVE does not exist. The following Python code is a hypothetical example that demonstrates how a vulnerability matching the described pattern (arbitrary code execution via an unsafe `eval` on a configuration string) would be fixed. The fix involves replacing the unsafe `eval` with a dispatch table (an "allow-list") that maps expected string values to safe, pre-defined functions.

```python
import os

# The vulnerability described (e.g., CVE-2025-14926) would stem from
# unsafely executing code from a configuration file, for instance, using `eval()`.
# The proper fix is to replace such arbitrary code execution with a safe,
# allow-listed approach, as demonstrated below.

# 1. Define a set of pre-approved, safe operations.
# These functions are known to be safe and do not execute arbitrary strings.
def safe_log_model_details(config):
    """A safe, approved function that logs model details."""
    model_type = config.get("model_type", "unknown")
    print(f"[INFO] Processing model of type: {model_type}")

def safe_check_config_version(config):
    """A safe, approved function that checks a version number."""
    version = config.get("version", 1.0)
    if version < 2.0:
        print(f"[WARN] Configuration version {version} is considered legacy.")

# 2. Create an "allow-list" dispatch table.
# This maps expected string inputs from the config to the pre-vetted safe functions.
# Any input not in this dictionary will be rejected.
ALLOWED_POST_CONVERSION_HOOKS = {
    "log_details": safe_log_model_details,
    "check_version": safe_check_config_version,
}

# 3. Implement the patched `convert_config` function.
def convert_config(config_data: dict) -> dict:
    """
    Converts a model configuration, securely handling post-conversion hooks.
    This function represents the patched version that prevents code injection.
    
    The vulnerable version would have used `eval()` on 'post_conversion_hook'.
    This fixed version uses a safe dispatch table instead.
    """
    print("Starting configuration conversion...")
    converted_config = config_data.copy()
    converted_config["is_converted"] = True
    print("Core conversion logic finished.")

    # --- The Security Fix Implementation ---
    hook_name = config_data.get("post_conversion_hook")

    if hook_name:
        print(f"Found post-conversion hook request: '{hook_name}'")
        
        # Securely fetch the function from the allow-list.
        # .get() returns None if the key doesn't exist.
        safe_function_to_run = ALLOWED_POST_CONVERSION_HOOKS.get(hook_name)

        if safe_function_to_run:
            # If the hook name is in our allow-list, execute the corresponding safe function.
            print(f"Executing allowed hook: '{hook_name}'...")
            safe_function_to_run(converted_config)
        else:
            # If the hook name is not in the allow-list, reject it.
            # This is the crucial step that prevents arbitrary code execution.
            print(f"[SECURITY ERROR] Disallowed or unknown hook: '{hook_name}'. Skipping execution.")
    
    print("Configuration conversion process complete.\n")
    return converted_config

# --- Demonstration of the Fix ---

if __name__ == "__main__":
    # Example 1: A benign configuration with a valid, allowed hook.
    # The fix allows this to execute as intended.
    benign_config = {
        "model_type": "SEW",
        "version": 1.0,
        "post_conversion_hook": "check_version"
    }

    print("--- 1. Testing with a Benign Configuration ---")
    convert_config(benign_config)

    # Example 2: A malicious configuration attempting Remote Code Execution.
    # The payload attempts to use `os.system` to print a message.
    # In a vulnerable system using `eval`, this would execute.
    # The fixed `convert_config` will identify it as a disallowed hook and reject it.
    malicious_config = {
        "model_type": "malicious-model",
        "version": 99.0,
        "post_conversion_hook": "__import__('os').system('echo VULNERABILITY EXPLOITED!')"
    }

    print("--- 2. Testing with a Malicious Configuration ---")
    convert_config(malicious_config)

    # Example of what the vulnerable code might have looked like (FOR ILLUSTRATION ONLY - DO NOT USE):
    #
    # def vulnerable_convert_config(config_data: dict):
    #     hook_name = config_data.get("post_conversion_hook")
    #     if hook_name:
    #         # UNSAFE: Executes any string from the config file, leading to RCE.
    #         eval(hook_name)
    #     return config_data