Trixbox 2.8.0.4 is vulnerable to OS command injection via shell metacharacters in the lang parameter to /maint/modules/home/index.php.
View the template here CVE-2017-14535.yaml
References:
https://secur1tyadvisory.wordpress.com/2018/02/11/trixbox-os-command-injection-vulnerability-cve-2017-14535/