---
title: Host Apps On Different Hostnames
impact: MEDIUM
impactDescription: prevents cookie leaking and same-origin issues
tags: architecture, deployment, security, csharp
---

## Host Apps On Different Hostnames

Don't host untrusted content on the same domain as sensitive apps.

**Incorrect:**

```
App: example.com
User Content: example.com/uploads/malicious.html (Can read cookies via XSS)
```

**Correct:**

```
App: app.example.com
User Content: user-content.com
```

**Tools:** Architecture Review