GFI MailEssentials AI versions prior to 22.4 contain an arbitrary directory existence enumeration vulnerability in the ListServer.IsPathExist() web method exposed at /MailEssentials/pages/MailSecurity/ListServer.aspx/IsPathExist. An authenticated user can supply an unrestricted filesystem path via the JSON key "path", which is URL-decoded and passed to Directory.Exists(), allowing the attacker to determine whether arbitrary directories exist on the server.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:LVI:NVA:NSubsequent System
SC:NSI:NSA:N5.3/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NOther