security-review-owasp-securing-cascading-style-sheets

Review CSS stylesheets for access control, selector disclosure, and overlay abuse risks.

Updated Mar 26, 2026

Search Tags:#frontend #owasp #css #access control #security review #selector leakage #overlay abuse

Ready to run

npx skills add https://github.com/sjinks/ai-owasp-skillset --skill security-review-owasp-securing-cascading-style-sheets

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: security-review-owasp-securing-cascading-style-sheets
Source: https://github.com/sjinks/ai-owasp-skillset/tree/main/.github/skills/security-review-owasp-securing-cascading-style-sheets
Command: npx skills add https://github.com/sjinks/ai-owasp-skillset --skill security-review-owasp-securing-cascading-style-sheets

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill helps reviewers evaluate CSS security risks such as privileged style leakage, unauthorized stylesheet exposure, and user-controlled styling abuse.

Core Features & Use Cases

Access Control Review: Check whether role-specific or environment-specific stylesheets are protected from unauthorized access.
Selector Disclosure Review: Inspect class names, IDs, and selector patterns that may reveal hidden workflows or privileged capabilities.
User-Controlled Styling Review: Assess whether user content, uploads, or injected markup can drive overlays, deceptive layouts, or clickjacking-like behavior.
Use Case: Use this Skill when auditing a frontend feature, design system, or content pipeline for CSS-based reconnaissance and visual deception risks.

Quick Start

Use the security-review-owasp-securing-cascading-style-sheets skill to review the relevant CSS files and styling paths for leakage, access-control gaps, and overlay abuse.

Frequently Asked Questions about security-review-owasp-securing-cascading-style-sheets

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I review CSS for security risks like selector leakage and overlay abuse?▼

You can conduct a CSS security review by applying a checklist-driven procedure to stylesheets and frontend styling surfaces, identifying access control gaps, selector disclosure, and overlay abuse with OWASP-aligned output.

What is CSS selector disclosure and how does it reveal hidden workflows?▼

CSS selector disclosure occurs when class names, IDs, and selector patterns in stylesheets reveal hidden workflows or privileged capabilities, allowing attackers to map out unauthorized access paths through frontend styling reconnaissance.

How do I check whether role-specific stylesheets are protected from unauthorized access?▼

Perform an access control review to verify whether role-specific or environment-specific stylesheets are protected from unauthorized access, producing evidence-based findings for confirmed issues and passed checks.

Can user-controlled styling lead to clickjacking or deceptive layouts?▼

Yes, user-controlled styling abuse happens when user content, uploads, or injected markup drives overlays, deceptive layouts, or clickjacking-like behavior, and a user-controlled styling review assesses these visual deception risks.

Does this CSS security review cover both code and configuration surfaces?▼

The CSS security review covers access control, selector disclosure, user-controlled styling, and overlay abuse across code, configuration, architecture, and operational controls, generating OWASP-aligned output for confirmed issues and review gaps.

What are the limitations of using a checklist-driven approach for CSS security reviews?▼

A checklist-driven CSS security review requires evidence-based findings for confirmed issues, review gaps, and passed checks, meaning it is limited by the thoroughness of the checklist and the availability of concrete evidence across code and configuration.