This indicates an attack attempt to exploit an Elevation of Privilege vulnerability in Microsoft Exchange Server.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted application. A remote attacker may be able to exploit this to escalate their privileges on vulnerable systems.
Microsoft Exchange Server 2019
Microsoft Exchange Server 2016
Microsoft Exchange Server 2013
Microsoft Exchange Server 2010
Privilege Escalation: Remote attackers can leverage their privileges on vulnerable systems.
Apply the most recent upgrade or patch from the vendor.