It would be possible for someone to pass a value to the $template
variable that used ../
or /
to navigate out of the directory you have set in the parameter.
In theory they could navigate up to more vulnerable directories and access files you don't want them to.
I would say the best approach to secure against that would be to validate against the input string containing ../
or /
If you know the file name will never have any .
or /
characters in you could throw a validation error for any string containing any .
or /
characters.
On top of that, following best practices around setting up your users and permissions on your production server will help to protect you.
This thread offers some useful help there:
How to set up file permissions for Laravel?
Other than that I can't think of any other vulnerabilities... anyone else?