SS-2018-014: Dangerous file types in allowed upload
- Low (?)
- Versions Affected:
- silverstripe/framework:^3.6.5, silverstripe/framework:^4.0.3, silverstripe/framework:^4.1.0
- Versions Fixed:
- silverstripe/framework:3.6.6, silverstripe/framework:4.0.4, silverstripe/framework:4.1.1
- Release Date:
Some potentially dangerous file types exist in File.allowed_extensions which could allow a malicious CMS user to upload files that then get executed in the security context of the website. We have removed the ability to upload .css, .js, .potm, .dotm, .xltm and .jar files in the default configuration. Since allowed_extensions are synced to webserver configuration (in assets/.htaccess) automatically, this will also deny access to any existing uploads with these extensions.
Reported by Insomnia Security.