User controllable charset

  • The character encoding (charset) of this page is dirrectly controlled by user input. The charset can be specified in the Content-Type header or in a meta tag declaration. If an attacker can control the response charset, they could manipulate the HTML to perform XSS or other attacks.
  • It's recommended to force UTF-8 in charset declarations. If the user must control the charset, make sure you are using a whitelist of accepted charsets.