CVE-2022-30174: Microsoft 365 Apps RCE Vulnerability

CVE-2022-30174 Overview

CVE-2022-30174 is a Remote Code Execution vulnerability affecting Microsoft Office products. This vulnerability allows an attacker to execute arbitrary code on the target system when a user interacts with a specially crafted file. The attack requires local access and user interaction, meaning a victim must open a malicious document or file for the exploit to succeed.

Critical Impact

Successful exploitation could allow an attacker to execute arbitrary code with the privileges of the current user, potentially leading to complete system compromise, data theft, or further lateral movement within an organization's network.

Affected Products

• Microsoft 365 Apps for Enterprise
• Microsoft Office Long Term Servicing Channel 2021

Discovery Timeline

• 2022-06-15 - CVE-2022-30174 published to NVD
• 2025-01-02 - Last updated in NVD database

Technical Details for CVE-2022-30174

Vulnerability Analysis

This Remote Code Execution vulnerability in Microsoft Office allows attackers to execute arbitrary code on vulnerable systems. The attack requires local access and user interaction—specifically, a user must open a malicious Office document for exploitation to occur. While the attack complexity is low once the user opens the malicious file, the requirement for user interaction provides a potential mitigation point through security awareness training.

The vulnerability affects core Microsoft Office functionality and does not require any prior privileges for exploitation. Upon successful exploitation, an attacker gains the ability to compromise the confidentiality, integrity, and availability of the target system with the same privileges as the logged-in user. If the user has administrative rights, the attacker could gain full control of the affected system.

Root Cause

Microsoft has not disclosed the specific technical root cause of this vulnerability (classified as NVD-CWE-noinfo). Based on the vulnerability class and attack characteristics, this is likely related to improper handling or parsing of Office document components that allows code execution when processing specially crafted content.

Attack Vector

The attack vector for CVE-2022-30174 is local, requiring an attacker to deliver a malicious Office document to the victim. Common delivery methods include:

• Phishing emails with malicious Office document attachments
• Compromised websites hosting malicious files
• Social engineering to convince users to download and open malicious documents
• USB drives or network shares containing weaponized Office files

Once the victim opens the specially crafted document, the vulnerability is triggered without requiring any additional user interaction beyond the initial file opening. The malicious code executes in the context of the current user, meaning high-privilege accounts present greater risk.

Detection Methods for CVE-2022-30174

Indicators of Compromise

• Unusual Office application behavior including unexpected crashes or high CPU/memory usage
• Child processes spawned by Microsoft Office applications (e.g., cmd.exe, powershell.exe, or other executables spawned from WINWORD.EXE, EXCEL.EXE, or POWERPNT.EXE)
• Suspicious network connections originating from Office processes
• Unexpected file system modifications or new files created in temporary directories after opening Office documents

Detection Strategies

• Monitor for Office applications spawning suspicious child processes using endpoint detection rules
• Implement email gateway filtering to scan and quarantine suspicious Office document attachments
• Deploy behavioral analysis to detect anomalous Office application activity patterns
• Enable Windows Defender Attack Surface Reduction (ASR) rules for Office applications

Monitoring Recommendations

• Enable detailed logging for Microsoft Office applications and Windows Security events
• Configure SIEM alerts for Office processes initiating network connections or spawning command shells
• Implement file integrity monitoring on critical system directories
• Review endpoint telemetry for Office-related process trees that deviate from normal behavior

How to Mitigate CVE-2022-30174

Immediate Actions Required

• Apply the latest Microsoft security updates for all affected Office products immediately
• Enable Protected View for Office applications to prevent automatic execution of content from untrusted sources
• Implement application whitelisting to prevent unauthorized executables from running
• Educate users about the risks of opening Office documents from unknown or untrusted sources

Patch Information

Microsoft has released security updates to address this vulnerability. Organizations should apply the patches available through the Microsoft Security Update Guide. For detailed guidance and patch downloads, refer to the Microsoft Security Advisory for CVE-2022-30174.

Ensure that Microsoft 365 Apps for Enterprise and Office LTSC 2021 installations are updated to the latest available versions through Windows Update, Microsoft Update Catalog, or your organization's patch management solution.

Workarounds

• Enable Protected View for all Office applications to open documents in a sandboxed read-only mode
• Configure Office macro settings to disable macros or require digital signatures
• Use Microsoft Defender Attack Surface Reduction rules to block Office applications from creating executable content
• Restrict Office documents from untrusted locations using Group Policy

# Enable Protected View via Group Policy (recommended configuration)
# Navigate to: User Configuration > Administrative Templates > Microsoft Office > Security Settings
# Enable "Do not open files from the Internet zone in Protected View" = Disabled
# Enable "Do not open files in unsafe locations in Protected View" = Disabled

# Windows Defender ASR rules for Office protection (PowerShell)
Set-MpPreference -AttackSurfaceReductionRules_Ids 3B576869-A4EC-4529-8536-B80A7769E899 -AttackSurfaceReductionRules_Actions Enabled
Set-MpPreference -AttackSurfaceReductionRules_Ids 75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84 -AttackSurfaceReductionRules_Actions Enabled
Set-MpPreference -AttackSurfaceReductionRules_Ids D4F940AB-401B-4EFC-AADC-AD5F3C50688A -AttackSurfaceReductionRules_Actions Enabled