1. Content Security Policies (CSPs)
CSPs are browser-native tools that define which third-party domains are allowed to execute scripts. While useful in theory, CSPs have severe limitations:
- They don’t analyze script behavior, only the source URL.
- They fail to detect dynamic scripts that change based on user context.
- CSP violations cause console errors, which frustrate developers and reduce adoption.
As seen in the Polyfill attack just 6 months ago, trusting a source URL alone can be devastating.
2. Crawler-Based or "Scanner" Approaches
Crawler-based tools scan websites periodically to detect malicious scripts. This approach is reactive however, and easy to evade:
- Attackers easily detect and serve clean scripts to crawlers, bypassing detection.
- Crawler tools often sample traffic, which means attacks targeting a small percentage of users often go unnoticed.
- They cannot monitor user-specific sessions or capture the real script seen in the browser.
3. JS-Based Client-Side Detection
JS-based solutions monitor scripts within the browser but suffer from major flaws:
- They function essentially as traps, but the traps are visible so bad actors can circumvent detection.
- This approach lacks historical visibility meaning they cannot track script evolution over time or provide forensics.
With regulation like PCI DSS firmly requiring client-side controls, these techniques are used to quickly check the audit box. But they don’t provide true protection. They leave businesses exposed to sophisticated attacks that evolve faster than these tools can respond.
Read an in depth comparison and selection guide here.
What To Look for In a Client-side Security Tool
At cside, we’ve redefined client-side security by addressing the weaknesses of traditional approaches. Our unique proxy-based architecture enables:
- Script Behavior Analysis:
Unlike tools that sample traffic or rely on threat feeds, cside watches the behavior and data flow of all third-party scripts. This means:- cside sees what data scripts access and where they send it
- cside watches for DOM manipulations, JavaScript event listeners, and more.
- The Ability to Block Scripts
cside allows you to set policies that can block certain scripts based on behaviors or source domains. Scanners can not block scripts. CSP can block scripts but based on limited data. A true client-side security tool allows you to block threats before they become major breaches. - AI-Powered Script Analysis
Our platform leverages advanced AI models to analyze scripts intelligently and autonomously. Unlike static threat feeds, cside detects patterns that traditional tools miss, including:- Dynamic script injections.
- Evasive payloads tailored to specific geographies, IP addresses, or user sessions.
- Performance Impact
Security shouldn’t come at the cost of user experience. Check the deployment architecture of the client-side security solution you are evaluating and ask vendors what latency their tool adds to your website. - Compliance Dashboards
Meeting PCI DSS 4.0.1 requirements means that you need evidence formatted to auditor expectations. GDPR, CCPA, and other frameworks require client-side controls for data protection. Your client-side security tool should automatically shape collected data into framework-specific formats. cside offers this through premade dashboards, reports, and evidence logs that are formatted to regulation requirements. - Intuitive User Experience
Some cybersecurity dashboards still look like they were built in 2005. It's not about looking pretty, it's about your team easily accessing the information they need. Most teams are juggling multiple compliance frameworks and security surfaces. Deciphering an overwhelming dashboard just brings more mental overload. cside's dashboard was designed to be intuitive. We count how many clicks it takes to get to key information. Your security & compliance teams get quick notifications and actionable insights.
Why it matters for your business
If your business relies on third-party scripts, handles sensitive data, or processes online payments, the risks are alarming. The rise in “Magecart” attacks have proven that client-side vulnerabilities can cost millions in fines and lost revenue.
Here’s what’s at stake:
- Compliance: PCI DSS 4.0.1 mandates continuous script monitoring on payment pages.
- Financial Losses: Breaches can cripple a business with direct fines and customer churn.
- Reputation: 91% of customers won’t return to a business after a data breach.
Conclusion
If your business handles third-party scripts, processes payments, or values trust, the choice is clear: cside protects your customers, secures your business, and keeps you ahead of evolving threats.
Sign up for a free plan or talk to us to get a personalized recommendation for your client-side security strategy.
