MailEnable < 10.55 Reflected XSS via ManageShares.aspx SelectedIndex Parameter

MailEnable versions prior to 10.55 contain a reflected cross-site scripting vulnerability in the webmail interface that allows remote attackers to execute arbitrary JavaScript in a victim's browser by crafting a malicious URL. Attackers can inject malicious code through the SelectedIndex parameter in the ManageShares.aspx form, which is not properly sanitized before being embedded into dynamically generated JavaScript.