Common Front-End Security Attacks, Principles, and Mitigations

During interviews, many developers are asked about web security. This article introduces common front-end security attack types, their principles, and mitigation methods.

1. Cross-Site Scripting (XSS)

XSS injects malicious scripts into trusted pages, allowing attackers to steal tokens, cookies, and other sensitive data.

How to prevent XSS

Three main measures:

Validate and sanitize user input and encode output.

Implement Content Security Policy (CSP) to restrict loaded resources.

Use frameworks like Vue or React that have built‑in XSS protection.

2. SQL Injection

Attackers manipulate database queries to gain unauthorized access, potentially damaging or stealing data.

Prevention

Validate and sanitize front‑end input.

Never trust client data; validate on the back end and use scanning tools such as Burp, sqlmap, jSQL Injection, Invicti.

3. Cross-Site Request Forgery (CSRF)

CSRF tricks users into performing actions they did not intend.

Prevention

Use server‑generated CSRF tokens and frameworks with built‑in CSRF support (e.g., .NET, Spring Security, Ruby on Rails).

4. Man‑in‑the‑Middle (MITM)

Attackers intercept and modify traffic on insecure channels, often via public Wi‑Fi.

Prevention

Use secure internet connections and log out of unused applications.

Avoid unknown Wi‑Fi networks.

Encrypt all data in transit with HTTPS/TLS.

5. Clickjacking

Hidden elements overlay legitimate UI components, causing users to click unintended targets.

Prevention

Set the X-Frame-Options header to prevent your site from being embedded in other pages or iframes.

6. Security Misconfiguration

Improper defaults, outdated settings, and exposed error details can be exploited.

Prevention

Update default credentials and perform regular configuration audits.

Automate build and deployment pipelines with separate credentials for production, development, and testing environments.

7. Dependency Exploitation

Third‑party libraries may contain vulnerabilities that attackers can leverage.

Prevention

Use well‑maintained, widely adopted libraries, regularly audit dependencies, and run vulnerability scanning tools.