Content Security Policy Cheat Sheet

Content Security Policy (CSP) is an important standard that is aimed to prevent attacks such as cross-site scripting (XSS) and more importantly to reduce the harm caused by content injection attacks.

Introduction

Introduction to CSP here.

80% Solution Policy

This allows inline javascript and styles while ensuring flash and mixed content can't happen.

default-src 'self'; font-src data: 'self'; img-src data: https:
'self'; media-src *; object-src 'none'; script-src 'self'
'unsafe-inline'; style-src 'self' 'unsafe-inline'; report-uri ???

[todo] adding eval [todo] adding a CDN, for example [todo] Add instructions for google analytics/translation

Configurations

[todo] add context around these examples and where they would go in a config file.

Apache

Header set X-Content-Type-Options "nosniff"
Header set X-XSS-Protection "1; mode=block"
Header set X-Frame-Options "SAMEORIGIN"
Header set Strict-Transport-Security "max-age=631138519"
Header unset Content-Security-Policy
Header add Content-Security-Policy-Report-Only <whatever the policy ends up being>

nginx

add_header X-Content-Type-Options "nosniff";
add_header X-XSS-Protection "1; mode=block";
add_header X-Frame-Options "SAMEORIGIN"; 
add_header Strict-Transport-Security "max-age=631138519"; 
add_header Content-Security-Policy-Report-Only <whatever the policy
ends up being>

Authors and Primary Editors

Neil Mattatall - neil[at]owasp.org
Denis Mello - ddtaxe

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