CVE-2024-21413 Microsoft Outlook Improper Input Validation
Attackers can execute arbitrary code via malicious emails in Microsoft Outlook, requiring users to apply vendor patches.
- Exploited in the wild
- Since 6 Feb 2025
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-21413?
CVE-2024-21413 is a critical code injection vulnerability in Microsoft 365 Apps, published on 13 Feb 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Microsoft Outlook Remote Code Execution Vulnerability
Weakness: CWE-20
Which versions are affected by CVE-2024-21413?
It affects 4 products.
Products include Microsoft 365 Apps, Microsoft Office 2016, Microsoft Office 2019, Microsoft Office Long Term Servicing Channel.
How do I fix CVE-2024-21413?
No fix has been published for CVE-2024-21413 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 27 Feb 2025.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2024-21413 being exploited?
Yes. Attackers have exploited CVE-2024-21413 in the wild since at least 6 Feb 2025.
Public exploit code: 42 proofs of concept on GitHub.
Other vulnerabilities in Microsoft 365 Apps
- CVE-2023-23397 Microsoft Office Outlook Privilege Escalation
- CVE-2024-38189 Microsoft Project Remote Code Execution Vulnerability
- CVE-2023-35311 Microsoft Outlook Security Feature Bypass
- CVE-2026-21514 Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision
- CVE-2026-21509 Microsoft Office Security Feature Bypass
Sources
Also known as GHSA-9mp4-h7q5-2rgq.