This article explains how developers’ common misconfigurations in Content Security Policies (CSPs) create vulnerabilities for Cross-Site Scripting (XSS) exploits. It provides detailed techniques to identify and bypass weak CSPs, highlighting the importance of thorough analysis for bug bounty hunting. #ContentSecurityPolicy #XSSBugs
Keypoints
- Many CSPs in the wild are improperly configured, leaving loopholes for attackers.
- Common misconfigurations include the use of ‘unsafe-inline’, wildcard domains, and missing directives like ‘base-uri’.
- Systematic auditing involves reviewing CSP headers, identifying trusted domains, and testing for JSONP, file uploads, and HTML injections.
- Advanced bypass techniques include exploiting ‘unsafe-eval’ and manipulating ‘base-uri’ to redirect scripts.
- Creating a strong CSP involves restrictive policies with nonces, strict directives, and minimized trusted domains to prevent exploits.