CVE-2024-21413
KEVMicrosoft Outlook Improper Input Validation Vulnerability
Description
Microsoft Outlook contains an improper input validation vulnerability that allows for remote code execution. Successful exploitation of this vulnerability would allow an attacker to bypass the Office Protected View and open in editing mode rather than protected mode.
Microsoft Outlook Remote Code Execution Vulnerability
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HPublishedFeb 13, 2024
Last modifiedAug 10, 2026
Added to KEVFeb 6, 2025
Remediation dueFeb 27, 2025
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413PatchVendor Advisory
- research.checkpoint.com/2024/the-risks-of-the-monikerlink-bug-in-microsoft-outlook-and-the-big-picture/Technical Description
- vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-detection-scriptExploit
- vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vulnerability-affecting-microsoft-outlook-mitigation-scriptMitigation
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21413US Government Resource
0 recent articles mention this CVE
88
Risk assessment · Critical
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 606 days
- CVSS
- 9.8 CRITICAL
- EPSS (30-day exploit probability)
- 94.7% · top 1% of all CVEs
- Weakness
- CWE-20
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.