GFI MailEssentials AI < 22.4 Anti-Spam URI DNS Blocklist Domain Stored XSS

GFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the URI DNS Blocklist configuration page. An authenticated user can supply HTML/JavaScript in the ctl00$ContentPlaceHolder1$pv1$TXB_URIs parameter to /MailEssentials/pages/MailSecurity/uridnsblocklist.aspx, which is stored and later rendered in the management interface, allowing script execution in the context of a logged-in user.