The flaw is an improper authorization in the WebAdmin mobile portal that lets an attacker replay an authentication token issued for a low‑privileged user across the portal boundary. By sending the same AuthenticationToken cookie captured from the WebMail login endpoint, the attacker can bypass the WebAdmin authentication checks and carry out any high‑privileged administrative operation. This bug falls under CWE‑639 and can lead to full administrative takeover of the MailEnable server.

This issue affects MailEnable Enterprise Premium versions 10.55 and earlier. The vulnerability is confined to the WebAdmin mobile portal component of the Enterprise Premium edition; other MailEnable products or newer Enterprise Premium releases are not affected.

The CVSS score of 8.7 classifies the flaw as high severity, and because no active exploit is reported in the KEV catalog the risk is primarily theoretical. An attacker would need to obtain or forge an AuthenticationToken cookie for a low‑privileged user – for example by logging in to the WebMail interface with valid credentials or intercepting the cookie – and then replay it against the WebAdmin endpoint. The ability to perform privileged actions makes this a serious threat, especially in environments where JavaScript‑enabled browsers are used. Therefore, organizations should treat this as a critical security concern while a patch is applied.