CVE-2022-24511: Microsoft 365 Apps Tampering Vulnerability

CVE-2022-24511 Overview

CVE-2022-24511 is a tampering vulnerability affecting Microsoft Office Word that allows an attacker to potentially access confidential information through a locally executed attack. This vulnerability requires user interaction, typically through opening a maliciously crafted document, which can lead to unauthorized disclosure of sensitive data stored on the affected system.

Critical Impact

This tampering vulnerability in Microsoft Word could allow attackers to gain unauthorized access to confidential information when a user opens a specially crafted document, potentially exposing sensitive corporate or personal data.

Affected Products

• Microsoft 365 Apps (Enterprise)
• Microsoft Office 2019
• Microsoft Office 2021 LTSC
• Microsoft Word 2013 SP1
• Microsoft Word 2016

Discovery Timeline

• 2022-03-09 - CVE-2022-24511 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-24511

Vulnerability Analysis

This tampering vulnerability in Microsoft Office Word stems from improper handling of document content, which can lead to information disclosure. The vulnerability requires local access and user interaction to exploit—specifically, a victim must open a maliciously crafted Word document for the attack to succeed.

The attack scenario involves an attacker crafting a specially designed Word document that, when opened by an unsuspecting user, allows the attacker to access confidential information that should otherwise be protected. The vulnerability specifically impacts the confidentiality of data, with no direct impact on system integrity or availability.

Root Cause

The vulnerability is classified as NVD-CWE-noinfo, indicating that specific details about the underlying weakness have not been publicly disclosed by Microsoft. However, based on the tampering classification and the confidentiality impact, the root cause likely involves improper validation or handling of document elements that can be manipulated to expose sensitive information during document processing.

Attack Vector

The attack vector for CVE-2022-24511 is local, requiring an attacker to either have direct access to the target system or convince a user to open a malicious document. The exploitation scenario typically involves:

1. An attacker crafts a malicious Word document designed to exploit the tampering vulnerability
2. The document is delivered to the victim through social engineering methods such as email attachments or file sharing
3. When the victim opens the document in Microsoft Word, the vulnerability is triggered
4. The attacker can then access confidential information from the victim's system

The attack has low complexity once the malicious document reaches the target user, requiring no special privileges but necessitating user interaction through opening the crafted file.

Detection Methods for CVE-2022-24511

Indicators of Compromise

• Unusual Word document files with unexpected embedded content or suspicious macro activity
• Microsoft Word processes accessing files or directories outside normal operational scope
• Unexpected network connections initiated by Word processes during document opening
• Anomalous file system access patterns when processing Word documents

Detection Strategies

• Monitor for Microsoft Word opening documents from untrusted sources or email attachments
• Implement endpoint detection rules to identify Word processes exhibiting unusual file access behavior
• Deploy document inspection solutions to analyze Word files before they reach end users
• Enable Microsoft Office Protected View and monitor for attempts to bypass this security feature

Monitoring Recommendations

• Enable detailed logging for Microsoft Office application events in Windows Event Viewer
• Monitor for bulk document processing or repeated opening of similar malicious files
• Implement file integrity monitoring on sensitive directories that could be targeted
• Track user behavior patterns for anomalous document opening activity

How to Mitigate CVE-2022-24511

Immediate Actions Required

• Apply the latest Microsoft security updates for all affected Office products immediately
• Enable Protected View for documents originating from the internet, email attachments, and potentially unsafe locations
• Educate users about the risks of opening untrusted Word documents
• Implement application whitelisting to prevent execution of unauthorized Office content

Patch Information

Microsoft has released security updates to address CVE-2022-24511. Detailed patch information and download links are available through the Microsoft Security Update Guide. Organizations should prioritize deploying these updates across all affected products including Microsoft 365 Apps, Office 2019, Office 2021 LTSC, Word 2013 SP1, and Word 2016.

Workarounds

• Configure Microsoft Office to open documents from untrusted sources in Protected View
• Disable trust for documents originating from the internet by default
• Implement email filtering to quarantine or block suspicious Word document attachments
• Use Microsoft Attack Surface Reduction (ASR) rules to limit Office application behaviors

# Enable Protected View settings via Group Policy
# Navigate to: User Configuration > Administrative Templates > Microsoft Word > Word Options > Security > Trust Center
# Enable: "Set document behavior if file validation fails" - Set to "Block files"
# Enable: "Block files from the Internet zone"