Known exploited vulnerability
CVE-2024-21413
The short answer
CVE-2024-21413 affects Microsoft Microsoft 365 Apps for Enterprise and is rated critical (CVSS 9.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2025-02-06: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
Microsoft Outlook Remote Code Execution Vulnerability
Weakness: CWE-20.
Severity
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Feb 6, 2025
Federal due date Feb 27, 2025
EPSS, next 30 days
95%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected products
Microsoft 365 Apps for Enterprise, Microsoft Office 2016, Microsoft Office 2019, Microsoft Office LTSC 2021. NVD's record lists the exact affected versions.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 PatchVendor Advisory
- msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 PatchVendor Advisory
- research.checkpoint.com/2024/the-risks-of-the-monikerlink-bug-in-microsoft-outlook-and-the-big-picture/ Technical Description
- www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-detection-script Exploit
- www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-mitigation-script Mitigation
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21413 US Government Resource
Questions
Is CVE-2024-21413 being exploited?
Yes. CISA added CVE-2024-21413 to its Known Exploited Vulnerabilities catalog on 2025-02-06, with a federal remediation due date of 2025-02-27.
How do I fix CVE-2024-21413?
CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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