Impact

A back end user with access to the form generator can upload arbitrary files and execute them on the server.

Patches

Update to Contao 4.4.46 or 4.8.6.

Workarounds

Configure your web server so it does not execute PHP files and other scripts in the Contao file upload directory.

References

https://contao.org/en/security-advisories/unrestricted-file-uploads

For more information

If you have any questions or comments about this advisory, open an issue in contao/contao.