Client-side security is on the rise. With the growing need for 3rd-party scripts, the risks grow in parallel. Attackers no longer need to breach your server or backend, they exploit scripts loaded in your users’ browsers. Through these, they can steal sensitive data, compromise payments, and undermine trust.
Businesses need to implement client-side solutions to mitigate these risks, but here’s the reality: not all client-side security solutions are created equal.
Some vendors rely on outdated methods or partial coverage, which leave businesses exposed to critical gaps. At c/side, we take a fundamentally different approach. By combining full payload visibility, real-time blocking, historical tracking, and intuitive reporting, we ensure client-side threats are identified and stopped before they cause damage.
The building blocks of client-side solutions
- Reliance on 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 payloads, only the source URL.
- They fail to detect dynamic scripts that change based on user context.
- Attackers can serve clean scripts to crawlers while delivering malicious payloads to real users.
- 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 can be devastating.
- Crawler-Based 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.
- JS-Based Client-Side Detection JS-based solutions monitor scripts within the browser but suffer from major flaws:
- They focus only on behavioral monitoring, failing to capture the exact payload delivered to users.
- They function essentially as traps, but the traps are visible so bad actors can easily circumvent detection with little effort.
- Most tools lack historical visibility—meaning they cannot track script evolution over time or provide forensics.
With regulation like PCI DSS on the horizon, tools using these techniques likely check the box. But they don’t provide true protection. They leave businesses exposed to sophisticated attacks that evolve faster than these tools can respond.
How it should be done
At c/side, we’ve redefined client-side security by addressing the weaknesses of traditional approaches. Our unique proxy-based architecture enables:
- Full Payload VisibilityUnlike tools that sample traffic or rely on threat feeds, c/side sits directly in the execution flow of all third-party scripts. This means:
- We see the exact payload delivered to the user’s browser—no guesswork, no evasion.
- 100% certainty that scripts reviewed are the ones seen by the user.
- Real-Time Threat Detection and Blockingc/side proactively monitors script behavior in real time and on every request. The moment a script exhibits malicious or suspicious activity, it’s blocked instantly. There’s no reliance on periodic scans or delayed reporting.
- Forensics and Historical Trackingc/side doesn’t just monitor scripts—it stores them. By tracking how scripts change over time, we:
- Identify emerging threats by analyzing subtle behavior shifts.
- Provide detailed forensics for past incidents, so businesses can understand what happened and how.
- AI-Powered Script AnalysisOur platform leverages advanced AI models to analyze scripts intelligently and autonomously. Unlike static threat feeds, c/side detects patterns that traditional tools miss, including:
- Dynamic script injections.
- Evasive payloads tailored to specific geographies, IP addresses, or user sessions.
- Performance OptimizationSecurity shouldn’t come at the cost of user experience. c/side’s proxy-based architecture optimizes script delivery with caching and modern protocols (HTTP/2 and HTTP/3), reducing latency while improving site performance. Fetch times can drop to 48ms on average.
- A PCI Dashboard for ComplianceMeeting PCI DSS 4.0 requirements has never been easier. c/side’s intuitive PCI dashboard provides real-time visibility into script activity, risk levels, and compliance status. For businesses processing payments, this eliminates the headaches of manual audits and reduces the risk of non-compliance fines.
- Intuitive User ExperienceWe’ve built c/side with modern security teams in mind. Our dashboard provides human-readable notifications and actionable insights. Security experts no longer need to decipher cryptic alerts—c/side tells you exactly what a script is doing and why it’s a threat.
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, lost revenue, and irreparable reputational damage.
Here’s what’s at stake:
- Compliance: PCI DSS 4.0 mandates continuous script monitoring—not just occasional audits.
- Financial Losses: Breaches can cripple a business with direct fines, lawsuits, and customer churn.
- Reputation: 91% of customers won’t return to a business after a data breach.
With c/side, you don’t just meet compliance. You gain unmatched protection, performance, and peace of mind.
The take away
Not all client-side security solutions are made equal. While most rely on outdated methods or reactive tools, c/side’s proxy-based architecture delivers real-time visibility, proactive blocking, and advanced AI-driven analysis.
If your business handles third-party scripts, processes payments, or values trust, the choice is clear: c/side protects your customers, secures your business, and keeps you ahead of evolving threats.
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