software/apt-lib.pl in Webmin before 1.997 lacks HTML escaping for a UI command.
https://www.exploit-db.com/exploits/50998
https://github.com/webmin/webmin/compare/1.996...1.997
https://github.com/webmin/webmin/commit/13f7bf9621a82d93f1e9dbd838d1e22020221bde
http://packetstormsecurity.com/files/167894/Webmin-1.996-Remote-Code-Execution.html