Cascade File Upload Without Validation

1. Cascade removed file type validation - accepts any file extension
2. Files saved directly to web root without sanitization
3. Cascade removed file size limits, allowing disk exhaustion
4. Filenames not sanitized - can contain path traversal sequences (../)

Validate file types by checking MIME type and extension whitelist. Limit file size (e.g., 10MB). Sanitize filenames to prevent path traversal. Store files outside web root if possible. Set proper permissions so files can't be executed. Virus scan uploads if dealing with user files. Generate random filenames.