The Truth About Client-Side Risk: 
What Security Vendors Don't Tell You

Register Now!
PCI-PPO-Statement

August 12th at 2:00 PM ET

 Your Security Stack May Stop at the Browser.

See how CSP, SRI, WAFs, RASP, monitoring tools, and behavior-based protection compare when customer data is exposed to third-party JavaScript.

Trusted Code Can Still Create Untrusted Outcomes

Modern websites depend on JavaScript for payments, analytics, personalization, chat, tag management, and testing. Much of that code comes from outside the organization and can load additional fourth-party scripts without direct approval.

Once a script runs in the browser, it may be able to read form fields, capture user activity, modify page content, or send data to an external destination.

Traditional security tools may confirm that a request is allowed, a file came from an approved source, or an application is behaving normally on the server. Those checks do not always reveal what an authorized script is doing inside the customer’s browser.

A Familiar Control Can Still Leave a Coverage Gap

CSP can restrict where scripts load from, but an allowlisted vendor can still be compromised. SRI can verify static files, but many third-party scripts change frequently or generate dynamic content.

WAF and RASP controls protect important parts of the application stack, but they generally do not control third-party JavaScript after it begins executing in the browser.

Monitoring platforms can surface changes or suspicious activity. The harder question is what happens while the team reviews the alert. Can the tool prevent the script from reading or transmitting sensitive data during that session?

Learn How the Approaches Compare

This webinar provides a practical comparison of the client-side security approaches enterprises are evaluating today. Rather than relying on product categories or vendor claims, the session will examine each approach against the controls that matter:

  • Runtime visibility
  • Protection from compromised trusted scripts
  • Control over sensitive form fields
  • Coverage for dynamic third-party code
  • Prevention versus alerting
  • PCI DSS support
  • Deployment and maintenance effort
  • Impact on website functionality

What You’ll Learn

  • Why server-side controls cannot provide complete visibility into browser activity
  • Where CSP provides value and where allowlist-based policies can fail
  • Why SRI is difficult to maintain for dynamic third-party scripts
  • How monitor-only tools differ from prevention-first controls
  • What behavior-based protection can control during script execution
  • How to compare vendor claims against PCI DSS 6.4.3 and 11.6.1
  • Which questions procurement should ask before approving a client-side security platform
Source Defense, 2026