Endpoint Vulnerability

Microsoft Exchange Server Elevation of Privilege Vulnerability


An elevation of privilege vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could gain the same rights as any other user of the Exchange server. This could allow the attacker to perform activities such as accessing the mailboxes of other users. Exploitation of this vulnerability requires Exchange Web Services (EWS) to be enabled and in use in an affected environment. To exploit the vulnerability, an attacker would need to change parameters in the Security Access Token and forward it to a Microsoft Exchange Server, thereby allowing impersonation of another Exchange user. To address this vulnerability, Microsoft has changed the way EWS handles these tokens.

Affected Products

Microsoft Exchange Server 2013 Cumulative Update 23,Microsoft Exchange Server 2019 Cumulative Update 3,Microsoft Exchange Server 2016 Cumulative Update 15,Microsoft Exchange Server 2016 Cumulative Update 14,Microsoft Exchange Server 2019 Cumulative Update 4