⚠ Actively exploited
Added to CISA KEV on 2025-02-06. Federal agencies required to patch by 2025-02-27. Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable..

CVE-2024-21413 — MonikerLink: Improper Input Validation in Microsoft 365 Apps FOR Enterprise

CWE-20 — Improper Input Validation9 documents8 sources
Severity
9.8CRITICALNVD
EPSS
93.0%
top 0.22%
CISA KEV
KEV
Added 2025-02-06
Due 2025-02-27
Exploit
Exploited in wild
Active exploitation observed
Affected products
5
Microsoft 365 Apps FOR EnterpriseMicrosoft Office 2016Microsoft Office 2019+2 more
Timeline
PublishedFeb 13
KEV addedFeb 6
KEV dueFeb 27
CISA Required Action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Description

Microsoft Outlook Remote Code Execution Vulnerability

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages5 packages

▶CVEListV5microsoft/microsoft_office_201616.0.0 — 16.0.5435.1001
▶CVEListV5microsoft/microsoft_office_201919.0.0 — https://aka.ms/OfficeSecurityReleases
▶CVEListV5microsoft/microsoft_office_ltsc_202116.0.1 — https://aka.ms/OfficeSecurityReleases
▶CVEListV5microsoft/microsoft_365_apps_for_enterprise16.0.1 — https://aka.ms/OfficeSecurityReleases

Patches

Patch: msrc.microsoft.com ↗Patch: msrc.microsoft.com ↗

🔴Vulnerability Details

3
CVEList
Microsoft Outlook Remote Code Execution Vulnerability↗2024-02-13
▶
GHSA
GHSA-9mp4-h7q5-2rgq: Microsoft Outlook Remote Code Execution Vulnerability↗2024-02-13
▶
VulnCheck
Microsoft Outlook Improper Input Validation Vulnerability↗2024
▶

📋Vendor Advisories

2
CISA
Microsoft Outlook Improper Input Validation Vulnerability↗2025-02-06
▶
Microsoft
Microsoft Outlook Remote Code Execution Vulnerability↗2024-02-13
▶

🕵️Threat Intelligence

1
Bleepingcomputer
Critical RCE bug in Microsoft Outlook now exploited in attacks↗2025-02-06
▶

📄Research Papers

1
CTF
Mailing / README↗
▶
CVE-2024-21413 — MonikerLink: Improper Input Validation | cvebase