* Set `X-Content-Type-Options` by default to `nosniff`. * Set `X-XSS-Protection` by default to `1; mode=block` instead of `1`. * Set `Content-Security-Policy` to a restrictive value (depends on #3711). * Make all configurable similar as `X-Frame-Options` (see [ClickjackProtectionListener](https://github.com/zikula/core/blob/main/src/Zikula/Bundle/CoreBundle/EventListener/ClickjackProtectionListener.php#L57)). * https://content-security-policy.com/ * https://dev.to/jszutkowski/applying-content-security-policy-in-symfony-to-reduce-xss-risks-5a4l Refs #3646