CVE-2022-23252: Microsoft 365 Apps Info Disclosure Flaw

CVE-2022-23252 Overview

CVE-2022-23252 is an information disclosure vulnerability affecting multiple versions of Microsoft Office products. This vulnerability allows an attacker with local access to potentially read sensitive information that should be protected. The vulnerability affects a broad range of Microsoft Office installations, including Microsoft 365 Apps for Enterprise, Office 2013 SP1, Office 2016, Office 2019, and Office LTSC 2021.

Critical Impact

Successful exploitation could lead to unauthorized disclosure of sensitive information stored within or processed by Microsoft Office applications, potentially exposing confidential business data or personal information.

Affected Products

• Microsoft 365 Apps for Enterprise (x64 and x86)
• Microsoft Office 2013 SP1 (x64, x86, and RT)
• Microsoft Office 2016 (x64 and x86)
• Microsoft Office 2019 (x64 and x86)
• Microsoft Office Long Term Servicing Channel 2021

Discovery Timeline

• February 9, 2022 - CVE-2022-23252 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-23252

Vulnerability Analysis

This information disclosure vulnerability exists within Microsoft Office's handling of certain data operations. The flaw allows a locally authenticated attacker to read confidential information that the application should protect from unauthorized access. The vulnerability requires local access to the target system and low-level privileges to exploit, meaning an attacker would need some form of initial access to the victim's machine.

The impact is primarily on confidentiality—while the vulnerability does not enable an attacker to modify data or disrupt service availability, it could expose sensitive documents, cached credentials, or other protected information processed by Office applications. This type of vulnerability is particularly concerning in enterprise environments where Office applications regularly handle confidential business documents, financial data, and personal information.

Root Cause

The vulnerability stems from improper handling of sensitive data within Microsoft Office components. While Microsoft has not disclosed specific technical details about the root cause, information disclosure vulnerabilities in Office products typically arise from memory handling issues, improper access controls on temporary files, or flaws in how the application manages cached or processed data. The CWE classification indicates that no specific weakness enumeration has been assigned (NVD-CWE-noinfo), suggesting Microsoft has not publicly detailed the exact technical mechanism.

Attack Vector

The attack vector for CVE-2022-23252 is local, meaning exploitation requires the attacker to have existing access to the target system. This could occur through:

• A compromised user account on a shared workstation
• Malware that has already gained a foothold on the system
• Physical access to an unlocked or inadequately secured machine
• Exploitation chained with another vulnerability that provides initial local access

Once the attacker has local access with low-level privileges, they can exploit this vulnerability without requiring user interaction, making it potentially dangerous in multi-user environments or on systems where lower-privileged users may have malicious intent.

The vulnerability does not allow remote exploitation directly, which limits its immediate attack surface. However, attackers commonly chain local information disclosure vulnerabilities with other exploits to escalate their attack capabilities.

Detection Methods for CVE-2022-23252

Indicators of Compromise

• Unusual access patterns to Microsoft Office temporary files or cache directories
• Unexpected Office process behavior such as reading from protected memory regions
• Anomalous file access events from Office applications attempting to read system or user data outside normal scope

Detection Strategies

• Monitor Windows Event Logs for suspicious process activity involving Office applications (WINWORD.EXE, EXCEL.EXE, POWERPNT.EXE, OUTLOOK.EXE)
• Implement endpoint detection rules to identify abnormal memory access patterns by Office processes
• Deploy file integrity monitoring on Office application directories and temporary file locations

Monitoring Recommendations

• Enable enhanced logging for Microsoft Office applications through Group Policy
• Monitor for lateral movement attempts following potential information disclosure events
• Correlate Office application activity with user login events to identify suspicious access from unusual accounts
• Review access logs for Office-related files and directories for unauthorized read operations

How to Mitigate CVE-2022-23252

Immediate Actions Required

• Apply the latest Microsoft security updates for all affected Office products immediately
• Verify patch deployment across all endpoints using vulnerability scanning or endpoint management tools
• Restrict local access privileges to minimize the attack surface for local exploitation vectors
• Ensure Office installations are configured to receive automatic updates

Patch Information

Microsoft has released security updates addressing this vulnerability as part of their February 2022 security release. Organizations should apply the appropriate updates based on their Office version:

• Microsoft 365 Apps: Update through the Office Update mechanism or Microsoft Update
• Office 2019 and Office LTSC 2021: Apply the latest cumulative update
• Office 2016: Install the corresponding security update
• Office 2013 SP1: Apply the latest security patches

For detailed patch information and download links, refer to the Microsoft Security Update Guide for CVE-2022-23252.

Workarounds

• Limit local access to systems running affected Office versions to only trusted users
• Implement application allowlisting to control which processes can interact with Office applications
• Use Microsoft Defender for Endpoint or equivalent EDR solutions to monitor for exploitation attempts
• Consider deploying Office applications in virtualized or sandboxed environments where sensitive data processing occurs

# Verify Office update status using PowerShell
# Check installed Office version and update status
Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Where-Object {$_.DisplayName -like "*Microsoft Office*"} | Select-Object DisplayName, DisplayVersion

# Force Office Click-to-Run update check
& "C:\Program Files\Common Files\Microsoft Shared\ClickToRun\OfficeC2RClient.exe" /update user