EventON < 4.4.1 - Reflected Cross-Site Scripting

Description The plugin does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin

PoC

Make a logged in admin open a page containing one of the code below: 2.6.x (the cmonth and cyear need to match an opened event) 3.x.y and 4.x.y