What’s Vulnerable › Vulnerabilities

CVE-2020-16875: Microsoft Exchange Server Remote Code Execution Vulnerability

• Severity: critical (CVSS 9.0 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 46.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-09-11 · updated 2026-06-17
• Weakness: CWE-74

Description

<p>A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.</p> <p>An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. Exploitation of the vulnerability requires an authenticated user in a certain Exchange role to be compromised.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Exchange handles cmdlet arguments.</p>

Affected products

• Microsoft Exchange Server: 2016-cumulative_update_16, 2016-cumulative_update_17, 2019-cumulative_update_5, 2019-cumulative_update_6
• Microsoft Exchange Server 2016 Cumulative Update 16: from 15.01.0 before publication — fixed in publication
• Microsoft Exchange Server 2016 Cumulative Update 17: from 15.01.0 before publication — fixed in publication
• Microsoft Exchange Server 2019 Cumulative Update 5: from 15.02.0 before publication — fixed in publication
• Microsoft Exchange Server 2019 Cumulative Update 6: from 15.02.0 before publication — fixed in publication

How to fix

Upgrade to a fixed version: Microsoft Exchange Server 2016 Cumulative Update 16 publication; Microsoft Exchange Server 2016 Cumulative Update 17 publication; Microsoft Exchange Server 2019 Cumulative Update 5 publication; Microsoft Exchange Server 2019 Cumulative Update 6 publication. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/159210/Microsoft-Exchange-Server-DlpUtils-AddTenantDlpPolicy-Remote-Code-Execution.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16875
• http://packetstormsecurity.com/files/159210/Microsoft-Exchange-Server-DlpUtils-AddTenantDlpPolicy-Remote-Code-Execution.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16875

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