The "Content-Security-Policy" header is designed to modify the way browsers render pages, and thus to protect from various cross-site injections, including Cross-Site Scripting. Insecure values such as '', 'data:', 'unsafe-inline', or 'unsafe-eval' should be avoided. In addition, to protect against Cross-Frame Scripting or clickjacking, it is important to set the 'frame-ancestors' policy with proper values. Insecure values such as '' or 'data:' should be avoided. Setting this value properly is a compliance requirement for most enterprise installations.
Sample Content Security Policy Header: