Critical Vulnerability in Microsoft Outlook Allows Remote Code Execution

28 Mar 2026

MicrosoftOutlookCVE-2024-21413RemoteCodeExecutionCybersecurityVulnerabilityPatchFebruary2024UpdatesURLEncodingPathTraversalPayloadDeliveryWindows10Windows11TargetedAttacksPersistencePrivilegeEscalationSecurityUpdates

The video from @Underscore_ examines a critical vulnerability in Microsoft Outlook (CVE-2024-21413) that allows attackers to bypass Office Protected View and execute arbitrary code via malicious hyperlinks. The flaw, patched in Microsoft’s February 2024 updates, exploits the way Outlook processes specially crafted URLs containing the file:// protocol, enabling remote code execution without user interaction. Demonstrations show how attackers can craft emails with obfuscated links that evade detection, leveraging techniques like URL encoding and path traversal to deliver payloads. The vulnerability affects multiple Outlook versions, including those on Windows 10 and 11, and was actively exploited in targeted attacks prior to the patch. Technical details highlight the use of .url files and registry modifications to achieve persistence and privilege escalation. The presenter emphasizes the importance of applying the February 2024 security updates to mitigate the risk. No specific threat actors or affected organizations were named in the discussion.