Patched code sample

import os

def image_get_fixed(base_path, requested_path):
    """
    Retrieves an image file, preventing path traversal vulnerabilities.

    Args:
        base_path: The allowed base directory for image files.
        requested_path: The path to the image file requested by the user.

    Returns:
        The content of the image file as bytes, or None if the file is not found 
        or the requested path is invalid.
    """
    # Sanitize the requested path by removing any leading slashes and normalizing the path
    safe_path = os.path.normpath(requested_path)

    # Create the absolute path by joining the base path and the sanitized path
    absolute_path = os.path.abspath(os.path.join(base_path, safe_path))

    # Check if the absolute path is within the allowed base path.  Crucial security check!
    if not absolute_path.startswith(os.path.abspath(base_path)):
        print("Attempted path traversal!")
        return None  # Or raise an exception

    try:
        with open(absolute_path, 'rb') as f:  # Open in binary mode for images
            image_data = f.read()
        return image_data
    except FileNotFoundError:
        print(f"File not found: {absolute_path}")
        return None
    except Exception as e:
        print(f"Error reading file: {e}")
        return None

if __name__ == '__main__':
    # Example usage (replace with your actual base path)
    base_image_dir = "/path/to/your/image/directory"  # IMPORTANT: Set this to a safe directory
    os.makedirs(base_image_dir, exist_ok=True) #Creates the directory if it doesn't exist

    # Create a test image file (for demonstration)
    test_image_path = os.path.join(base_image_dir, "test_image.png")
    with open(test_image_path, "wb") as f:
        f.write(b"This is a dummy image file.")

    # Example 1: Valid request
    image_data = image_get_fixed(base_image_dir, "test_image.png")
    if image_data:
        print("Image data retrieved successfully.")

    # Example 2: Path traversal attempt
    image_data = image_get_fixed(base_image_dir, "../../../../../etc/passwd")  # Simulate attack
    if image_data is None:
        print("Path traversal attempt prevented.")

    #Example 3:  Traversal inside the base directory, but still avoids going outside
    os.makedirs(os.path.join(base_image_dir, "images"), exist_ok=True)
    image_data = image_get_fixed(base_image_dir, "images/../test_image.png")
    if image_data:
        print("Image data retrieved successfully (directory traversal inside base allowed)")