CVE-2021-31209: (Pwn2Own) Microsoft Exchange Server Missing Check of Message Integrity Vulnerability
Microsoft Exchange Server Spoofing Vulnerability
Other sources
This vulnerability allows network-adjacent attackers to tamper with update data on affected installations of Microsoft Exchange Server. User interaction is required to exploit this vulnerability. The specific flaw exists within the handling of Exchange Server Help updates. The issue results from a missing integrity check on update downloads. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2021-31209?
CVE-2021-31209 is a vulnerability in Microsoft Exchange Server that allows network-adjacent attackers to tamper with update data.
How severe is CVE-2021-31209?
CVE-2021-31209 has a severity rating of 6.5, which is considered high.
What is the affected software for CVE-2021-31209?
The affected software for CVE-2021-31209 includes Microsoft Exchange Server 2013, 2016, and 2019.
How can I fix CVE-2021-31209?
To fix CVE-2021-31209, apply the relevant patches or updates provided by Microsoft for your specific version of Exchange Server.
Where can I find more information about CVE-2021-31209?
You can find more information about CVE-2021-31209 on the Microsoft Security Response Center (MSRC) website and the Zero Day Initiative (ZDI) advisory.