A DOM based XSS in GFI Kerio Control v9.3.0 allows embedding of malicious code and manipulating the login page to send back a victim's cleartext credentials to an attacker via a login/?reason=failure&NTLM= URI.
https://www.youtube.com/watch?v=ZqqR89vzZ_I
https://twitter.com/haxel0rd/status/1174279811751174144
http://seclists.org/fulldisclosure/2019/Sep/35
http://packetstormsecurity.com/files/154678/GFI-Kerio-Control-9.3.0-Cross-Site-Scripting.html