Contain XSS Risks

The threat of Cross-Site Scripting (XSS) is well-known, but today’s security challenges run much deeper. Your attack surface now includes legacy systems you can't patch and third-party applications you don't control-all forming a complex ecosystem of code and dependencies.

This is where traditional defenses break down.

A Content Security Policy (CSP) is a crucial layer, but it's notoriously difficult to implement correctly and isn't available everywhere.

• You can't modify the CSP headers of the third-party SaaS apps your organization relies on.
• It's often impossible to patch or modify the code of legacy internal applications.
• This leaves you relying on the vendor to fix vulnerabilities-a slow process you have no control over.

When you can't control the server, you can't set the policy. Your organization is left exposed.

Webfuse Gives You Control-Without Touching the Backend

Webfuse applies outbound domain allowlists at the session level, ensuring compromised apps can’t leak data to unauthorized domains even if a malicious script executes.

Watch the full breakdown (above): In the 5-minute recorded session, see exactly how Webfuse contains these threats and gives you control over any application.

How Webfuse Solves This: The Lockdown App

Using Webfuse’s Lockdown App, you can: 

• Create a Granular Allowlist: Define precisely which domains your applications are permitted to communicate with (e.g., *.example.com, api.service.com). Learn how to create detailed rules in this article.
• Block Unauthorized Requests: Instantly prevent any navigation, script load, or API call to an unlisted domain. Any script attempting to violate this policy is automatically blocked.
• Apply Policies Instantly: Enforce these rules at the Virtual Web Session level without a single backend change.

Key Benefits

• Reduce the Impact of XSS Attacks: A rogue script may execute, but it can't exfiltrate data or communicate with an attacker's server. Its blast radius is contained.
• Secure Your Software Supply Chain: Drastically limit the risk from compromised third-party scripts by controlling exactly where they can send data.
• Protect Users of Any App: Apply robust security to SaaS platforms, vendor portals, and legacy applications-even those you don't host.

Sign Up & Get Started

Launch a SPACE with outbound domain restrictions in minutes.