What is client-side security?

Client-side security is a specialized segment of cybersecurity focused on protecting the parts of an application or website that interact directly with the user’s device. Unlike server-side security, which protects the back-end systems and data storage, client-side security aims to prevent attacks that compromise the user experience or data at the point of interaction.

Common examples of client-side attacks include digital skimming (Magecart), formjacking, and malicious redirects that compromise sensitive data.

Client-side security is about protecting the integrity of the scripts, assets, and code that run within a user’s browser. The goal is to monitor, detect, and block unauthorized scripts or injected code that could compromise data or application functionality. Client-side security tools help protect against threats by monitoring for malicious scripts, validating the integrity of assets, and controlling data-sharing pathways in real-time to prevent unauthorized access and tampering.

Key methods to protect against client-side attacks include the following:

• Monitoring JavaScript and third-party code to detect or block formjacking or skimming.
• Ensuring that channels that handle data sharing are secure.
• Deploying integrity checks to detect tampered code or unexpected script behavior, blocking attacks before they can execute.
• Implementing robust Content Security Policies (CSPs) to control which scripts and assets can load, reducing the risk of code injection or malicious redirects.

Harmful scripts designed to steal customer data don’t just damage a company’s brand and customer relationships, they can put a company in legal jeopardy. One of the most common effects of a client-side attack are data breaches, where personal customer information is leaked resulting in financial losses, identify loss, and poor publicity.

Of course, the predictable result is a loss of customer trust. However, companies that find themselves a victim of client-attack attacks are also subject to legal trouble and compliance violations. Data compliance laws like GDPR or CCPA strongly stipulate the ways in which companies must safeguard customer data.

Client-Side Defense is part of HUMAN’s Application Protection solutions, providing complete visibility and control of browser scripts, analyzing script behavior, detecting suspicious activity, and protecting data from unauthorized access — all without any interruption to the user experience.

Client-side – The security blindspot of your website

The client-side battle against JavaScript attacks is already here