🔄

Replit Security Guide

Online IDE with AI code generation

medium risk level

Replit's AI agent builds and deploys apps in its cloud environment. The shared hosting model and AI-generated code create unique security challenges — exposed ports, insufficient access controls, and secrets stored in plaintext Replit environment variables.

Common Vulnerabilities

high

Secrets visible in Replit environment

While Replit Secrets are encrypted, they're accessible to anyone with edit access to the Repl.

Limit collaborator access. Rotate secrets if shared with untrusted users.

medium

Exposed development ports

Replit exposes ports publicly by default, potentially leaking debug endpoints.

Ensure only production-ready endpoints are accessible. Disable debug modes.

high

Missing authentication on generated APIs

AI-generated Express/Flask APIs often lack auth middleware.

Add authentication to every route that accesses user data or performs mutations.

medium

Insecure file handling

Generated file upload handlers lack type validation and size limits.

Validate file types, enforce size limits, and store files outside the web root.

high

Hardcoded database connection strings

Database URLs with credentials appear directly in source code.

Move all connection strings to environment variables.

Pre-Launch Security Checklist

Move all secrets to Replit Secrets, not hardcoded in codeRequired
Verify only necessary ports are exposed
Add authentication middleware to all API routesRequired
Validate file uploads (type, size, content)
Remove all hardcoded connection stringsRequired
Disable debug mode in productionRequired
Review collaborator access levels
Add rate limiting to public endpoints
Check for exposed .env or config filesRequired
Test CORS configuration

Security Tips

1.

Use Replit's built-in Secrets manager — never put credentials in your code.

2.

Before sharing a Repl publicly, run Erzo's Secret Scanner on the entire codebase.

3.

Consider migrating to a dedicated hosting provider for production apps.

Scan your Replit app now

Erzo automatically detects these vulnerabilities and gives you actionable fixes.

    Erzo — AI Code Security Scanner | Error Zero