GFI MailEssentials AI < 22.4 Attachment Filtering Rule Stored XSS
GFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Attachment Filtering rule creation workflow. An authenticated user can supply HTML/JavaScript in the ctl00$ContentPlaceHolder1$pv1$TXB_RuleName parameter to /MailEssentials/pages/MailSecurity/attachmentchecking.aspx, which is stored and later rendered in the management interface, allowing script execution in the context of a logged-in user.