MS.Exchange.Server.UM.Core.Remote.Code.Execution

Description

This indicates an attack attempt to exploit a Remote Code Execution Vulnerability in Microsoft Exchange Server.
The vulnerability is due insufficient sanitization when handling a malicious configuration file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted text file.

Outbreak Alert

Joint Cybersecurity Advisory (CSA) has released the top Common Vulnerabilities and Exposures (CVEs) used since 2020 by Peoples Republic of China (PRC) state-sponsored cyber actors as assessed by the National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), and Federal Bureau of Investigation (FBI). Previously, FortiGuard labs has already published various Outbreaks Alerts included in the released CISA's advisory such as: Apache Log4j, Hikvision Webserver Vulnerability, Atlassian Confluence OGNL RCE Vulnerability, Microsoft Exchange Server RCE Vulnerabilities etc. See the full list at: https://www.fortiguard.com/outbreak-alert Links to dedicated reports on each published outbreak by FortiGuard Labs are added to Additional Resources section below.

View the full Outbreak Alert Report

Affected Products

Microsoft Exchange Server 2016 Cumulative Update 19
Microsoft Exchange Server 2019 Cumulative Update 8
Microsoft Exchange Server 2013 Cumulative Update 23
Microsoft Exchange Server 2019 Cumulative Update 7
Microsoft Exchange Server 2016 Cumulative Update 18
Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 31

Impact

System Compromise: Remote attackers can gain control of vulnerable systems.

Recommended Actions

Apply the most recent upgrade or patch from the vendor.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857

References