Threat Encyclopedia

MS.Exchange.Server.SecurityToken.Authentication.Bypass

description-logoDescription

This indicates an attack attempt to exploit a Privilege Elevation in Microsoft Exchange Server.
The vulnerability is due to insufficient sanitization when handling a malicious request. A remote attacker may be able to exploit this to perform configure action on a server's user mailboxes and ultimately disclose sensitive information on target user's mailbox via a crafted HTTP request.

affected-products-logoAffected Products

Microsoft Exchange Server 2019 Cumulative Update 8
Microsoft Exchange Server 2016 Cumulative Update 19
Microsoft Exchange Server 2016 Cumulative Update 20
Microsoft Exchange Server 2019 Cumulative Update 9
Microsoft Exchange Server 2013 Cumulative Update 23

Impact

Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.

recomended-action-logoRecommended Actions

Apply the most recent upgrade or patch from the vendor.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766

CVE References

CVE-2021-33766