Category

Client Side Security

Security vulnerabilities and automated fixes for client side security issues

4 posts found

high5 min

How DOM-based Cross-Site Scripting happens in JavaScript and how to fix it

A high-severity DOM-based XSS vulnerability in `public/audio_match_demo/index.html` allowed attackers to inject malicious JavaScript through manipulated song metadata from API responses. The fix replaces dangerous HTML string concatenation with secure DOM API methods that automatically escape content.

#xss#javascript#dom-api+3 more
A
anupamme
Aug 31, 2026
critical8 min

How Unsandboxed iframe Content Injection happens in JavaScript and how to fix it

A critical vulnerability in `app-viewer/js/LupineVault.js` allowed attacker-controlled HTML fetched from an external CDN to execute scripts in the application's full origin context by injecting it directly into an iframe's `srcdoc` attribute without any sandbox restrictions. The fix adds a `sandbox` attribute to the iframe element, restricting what the injected content can do even if it contains malicious scripts. This prevents cross-site scripting and origin-context script execution that could

#xss#javascript#iframe-sandbox+2 more
A
anupamme
Aug 26, 2026
critical5 min

How hardcoded API key exposure happens in JavaScript and how to fix it

A critical security vulnerability was discovered in `js/douban.js` where the Douban API key (`0ac44ae016490db2204ce0a042db2916`) was hardcoded directly in client-side JavaScript. This exposed the API credential to any user who could view the page source or use browser developer tools. The fix removed the hardcoded key, preventing unauthorized API access and potential abuse.

#security#javascript#api-keys+4 more
A
anupamme
Jul 28, 2026
critical6 min

How API key exposure in client-side HTML happens in JavaScript web applications and how to fix it

A critical security vulnerability was discovered in all.html where a Yandex Maps API key was embedded directly in client-side HTML at line 68. This pattern exposed API credentials to anyone viewing the page source, enabling unlimited unauthorized API requests. The fix removed the API key from the client-side code, demonstrating proper API key management for JavaScript applications.

#hardcoded-secrets#api-security#javascript+5 more
A
anupamme
Jul 27, 2026