This script is Copyright (C) 2009-2015 Tenable Network Security, Inc.
The remote FreeBSD host is missing a security-related update.
mybb team reports :
Input passed via avatar extensions is not properly sanitised before
being used in SQL queries. This can be exploited to manipulate SQL
queries by uploading specially named avatars.
The script allows to sign up with usernames containing zero width
space characters, which can be exploited to e.g. conduct spoofing
See also :
Update the affected package.
Risk factor :
High / CVSS Base Score : 7.5
CVSS Temporal Score : 7.1
Public Exploit Available : true