CVE-2024-21413: Microsoft Outlook RCE Vulnerability

CVE-2024-21413 Overview

Microsoft Outlook Remote Code Execution Vulnerability

Critical Impact
This vulnerability allows remote attackers to execute arbitrary code on affected systems, leading to potential loss of data, unauthorized access, or full system compromise.

Affected Products

Microsoft 365 Apps
Microsoft Office 2016
Microsoft Office 2019

Discovery Timeline

2024-02-13 - CVE-2024-21413 published to NVD
2025-10-28 - Last updated in NVD database

Technical Details for CVE-2024-21413

Vulnerability Analysis

CVE-2024-21413 is a remote code execution vulnerability affecting Microsoft Outlook. This flaw arises from improper handling of certain communication protocols, allowing attackers to execute arbitrary code remotely.

Root Cause

The vulnerability is caused by an input validation error within the “MonikerLink” handling mechanism which fails to properly sanitize network inputs, leading to arbitrary code execution.

Attack Vector

An attacker can exploit this vulnerability using crafted network packets to trigger the remote code execution, exploiting the vulnerable MonikerLink handler.

python

# Example exploitation code (sanitized)
import sys
import socket

def exploit(target_ip):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((target_ip, port))
    payload = "<exploit_payload_goes_here>"
    s.send(payload.encode())
    s.close()

if __name__ == "__main__":
    target_ip = sys.argv[1]
    exploit(target_ip)

Detection Methods for CVE-2024-21413

Indicators of Compromise

Unusual network traffic to unknown IP addresses
Suspicious process creation patterns
Unexplained system file modifications

Detection Strategies

Utilizing SentinelOne's behavior-based detection, anomalous execution patterns and deviation from normal application behavior related to Outlook can be detected effectively.

Monitoring Recommendations

Regularly monitor network traffic for anomalies and unwanted communications along with host-based Intrusion Detection Systems alerts around Outlook processes.

How to Mitigate CVE-2024-21413

Immediate Actions Required

Apply latest security patches from Microsoft
Update Microsoft Outlook to a secure version
Restrict network access to potentially vulnerable endpoints

Patch Information

Patches can be obtained from Microsoft's official advisory updates: Microsoft Security Update Guide

Workarounds

Disable vulnerable MonikerLink functionality via registry edits or group policy until the patch can be applied.

bash

# Configuration example
reg add "HKCU\Software\Policies\Microsoft\Office\16.0\Outlook\Security" /v DisableMonikerLink /t REG_DWORD /d 1 /f