CVE-2024-21413
Microsoft Outlook Improper Input Validation Vulnerability
Microsoft Office Outlook
Microsoft Outlook Remote Code Execution Vulnerability
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 6 February 2025. US federal agencies were required to remediate it by 27 February 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 94.7%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2024-21413 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2024-21413.
What does CVE-2024-21413 affect?
CVE-2024-21413 affects Microsoft Office Outlook. Microsoft Outlook Remote Code Execution Vulnerability
How severe is CVE-2024-21413?
CVE-2024-21413 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 94.7%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 27 February 2025.
How should organisations respond to CVE-2024-21413?
Apply the vendor patch for Microsoft Office Outlook as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.