Misconfigured Content Security Policy
TLDR: Misconfigured Content Security Policy (CSP), introduced in 2012, can expose web applications to XSS attacks, data injection, and resource hijacking. Issues such as overly permissive directives, improperly defined sources, or misaligned rules undermine the primary purpose of CSP, which is to control the sources of content that can be executed by a browser. A well-configured CSP is essential for robust web application security.
https://en.wikipedia.org/wiki/Content_Security_Policy
One frequent issue with misconfigured CSP is using overly broad directives like `default-src *` or `script-src 'unsafe-inline'`, which allow content from untrusted sources or inline scripts, negating the effectiveness of the policy. Another common problem is neglecting to include necessary resources in the policy, such as third-party APIs or CDN links, causing legitimate content to break. Mismanagement of reporting mechanisms, such as failing to configure the `report-uri` directive, can also result in a lack of visibility into policy violations.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP
To address these challenges, administrators should define a CSP that limits content sources to trusted origins and avoids unsafe practices like inline scripting. Tools like CSP Evaluator can help assess policy effectiveness and identify misconfigurations. Enabling the `report-uri` or `report-to` directives allows administrators to monitor violations and refine policies iteratively. Regular testing and adherence to best practices ensure that CSP implementations provide the intended level of security without disrupting application functionality.