Lovable
security
Insecure File Upload in Lovable App
Your Lovable app's file upload feature accepts any file type without validation, potentially allowing users to upload malicious scripts, executable files, or oversized files that could compromise your server or other users.
Without proper file validation, an attacker could upload a PHP script, an HTML file containing JavaScript, or a file disguised as an image that actually contains malware. If these files are served back to users, the malicious code could execute.
This is especially dangerous if uploaded files are stored in a publicly accessible location and served directly to users without content-type validation.
Error Messages You Might See
File type not allowed
413 Payload Too Large
Storage quota exceeded
Failed to upload file: permission denied
Common Causes
- No file type validation — The upload endpoint accepts any file regardless of extension or MIME type
- Client-side only validation — File type checks only happen in the browser, which can be easily bypassed
- No file size limits — Users can upload extremely large files, causing storage and bandwidth issues
- Files served with wrong content-type — Uploaded files are served back without proper Content-Type headers, allowing browser execution
- No malware scanning — Uploaded files are stored and served without any security scanning
How to Fix It
- Validate file types on the server — Check both file extension and MIME type on the backend, not just in the browser
- Set file size limits — Configure maximum upload sizes (e.g., 5MB for images, 25MB for documents)
- Rename uploaded files — Generate random filenames to prevent path traversal attacks
- Serve files with correct headers — Set Content-Type and Content-Disposition headers to prevent browser execution
- Use Supabase Storage policies — Configure bucket policies to restrict file types and sizes at the storage level
Real developers can help you.
Taufan
I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms.
Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact.
hanson1014
Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround.
Sage Fulcher
Hey I'm Sage! Im a Boston area software engineer who grew up in South Florida. Ive worked at a ton of cool places like a telehealth kidney care startup that took part in a billion dollar merger (Cricket health/Interwell health), a boutique design agency where I got to work on a ton of exciting startups including a photography education app, a collegiate Esports league and more (Philosophie), a data analytics as a service startup in Cambridge (MA) as well as at Phillips and MIT Lincoln Lab where I designed and developed novel network security visualizations and analytics. I've been writing code and furiously devoted to using computers to make people’s lives easier for about 17 years. My degree is in making computers make pretty lights and sounds. Outside of work I love hip hop, the Celtics, professional wrestling, magic the gathering, photography, drumming, and guitars (both making and playing them)
Jared Hasson
Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever
Rudra Bhikadiya
I build and fix web apps across Next.js, Node.js, and DBs.
Comfortable jumping into messy code, broken APIs, and mysterious bugs.
If your project works in theory but not in reality, I help close that gap.
Prakash Prajapati
I’m a Senior Python Developer specializing in building secure, scalable, and highly available systems. I work primarily with Python, Django, FastAPI, Docker, PostgreSQL, and modern AI tooling such as PydanticAI, focusing on clean architecture, strong design principles, and reliable DevOps practices. I enjoy solving complex engineering problems and designing systems that are maintainable, resilient, and built to scale.
MFox
Full-stack professional senior engineer (15+years). Extensive experience in software development, qa, and IP networking.
Tejas Chokhawala
Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript.
Focused on performance, clean architecture and shipping fast.
Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools.
Jaime Orts-Caroff
I'm a Senior Android developer, open to work in various fields
Krishna Sai Kuncha
Experienced Professional Full stack Developer with 8+ years of experience across react, python, js, ts, golang and react-native. Developed inhouse websearch tooling for AI before websearch was solved : )
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What file types should I allow?
Only allow the specific types your app needs. For profile pictures, allow only .jpg, .png, .webp. For documents, allow .pdf, .doc, .docx. Never allow .html, .js, .php, .exe, or .svg files from untrusted users.
Is Supabase Storage secure by default?
Supabase Storage requires you to set up bucket policies. By default, buckets are private, but you need to configure what file types and sizes are allowed, and who can upload.