CVE-2024-21413criticalunder attackCWE-20

CVE-2024-21413: critical vulnerability in Microsoft 365 Apps for Enterprise

Microsoft Outlook Remote Code Execution Vulnerability

Published 13 Feb 2024 · Updated 10 Aug 2026

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100Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA and has a public proof of concept.

ssvc Actcvss 9.8epss 95%

from disclosure to weapon2 days

Published on NVDFeb 13

1st PoC+2d

CISA KEV+359d

Action required by CISAfederal deadline: 2025-02-27

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

In short

A critical flaw in Microsoft Outlook allows attackers to execute arbitrary code on your computer by sending a specially crafted email message. This vulnerability requires no user interaction beyond opening the email and can completely compromise your system.

Technical detail

CWE-20 input validation vulnerability in Microsoft Outlook's email parsing mechanism enables unauthenticated remote code execution when processing maliciously crafted email content. The attack vector is network-based with no user privileges required; exploitation occurs during email parsing, leading to arbitrary code execution in the Outlook process context.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

Microsoft Outlook Remote Code Execution Vulnerability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Affected products

Microsoft · Microsoft 365 Apps for Enterprise Microsoft · Microsoft Office 2016 Microsoft · Microsoft Office 2019 Microsoft · Microsoft Office LTSC 2021

public PoCs found — 68

⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.

Related CVEs — Microsoft 365 Apps for Enterprise

In the same product, most dangerous first.

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References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 https://research.checkpoint.com/2024/the-risks-of-the-monikerlink-bug-in-microsoft-outlook-and-the-big-picture/https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21413 https://www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-detection-script https://www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-mitigation-script