CVE-2020-17144VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2020-17144: Microsoft Exchange Server Remote Code Execution Vulnerability

Affects Microsoft Exchange ServerSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 05/03/2022
EPSS: 36.5% chance of exploitation in 30 days – higher than 98% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2020-17144 (opens in a new tab)

Description

CVE-2020-17144 is a high-severity remote code execution vulnerability in Microsoft Exchange Server caused by improper validation of cmdlet arguments. This flaw allows an attacker to execute arbitrary code remotely on affected Exchange Server installations. The vulnerability has been exploited in the wild, indicating active threat usage. No specific affected versions or patch information is provided in the input data.

Summary

Microsoft Exchange Server contains a vulnerability (CVE-2020-17144) where improper validation of cmdlet arguments enables remote code execution by an attacker. This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). It has been observed to be exploited in the wild, posing a significant risk to affected systems. The input data does not specify which versions are affected or whether patches are available.

Impact

Successful exploitation of this vulnerability allows remote attackers to execute arbitrary code on Microsoft Exchange Server systems, potentially leading to full system compromise. Given that exploitation has been observed in the wild, the risk to organizations running vulnerable Exchange Server instances is high.

Mitigation

Patch status is not yet confirmed — check the Microsoft vendor advisory for current remediation guidance. Organizations should monitor official Microsoft security advisories for updates and apply any available patches promptly. Until patches are applied, restricting access to Exchange Server management interfaces and monitoring for suspicious activity may help reduce risk.

Weaknesses

CWE-502Deserialization of Untrusted Data (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:19:36 UTC

Weaknesses

References

Related threats