CVE-2025-62562: Microsoft 365 Apps Use-After-Free Flaw

CVE-2025-62562 Overview

CVE-2025-62562 is a use-after-free vulnerability in Microsoft Office Outlook that allows an unauthorized attacker to execute arbitrary code locally. This memory corruption flaw occurs when the application continues to reference memory that has already been freed, enabling attackers to manipulate program execution flow and potentially gain control of the affected system.

Critical Impact

Successful exploitation of this use-after-free vulnerability could allow an attacker to execute arbitrary code with the privileges of the current user, potentially leading to complete system compromise, data theft, or installation of malware.

Affected Products

• Microsoft 365 Apps (Enterprise x64 and x86)
• Microsoft Office 2019 (x64 and x86)
• Microsoft Office Long Term Servicing Channel 2021 and 2024 (Windows x64/x86 and macOS)
• Microsoft SharePoint Server 2016 Enterprise and 2019
• Microsoft Word 2016 (x64 and x86)

Discovery Timeline

• 2025-12-09 - CVE CVE-2025-62562 published to NVD
• 2025-12-09 - Last updated in NVD database

Technical Details for CVE-2025-62562

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption issue that arises when an application continues to use a pointer after the memory it references has been deallocated. In the context of Microsoft Office Outlook, this flaw can be triggered when processing specially crafted content, allowing an attacker to corrupt memory and redirect code execution.

The local attack vector requires user interaction, meaning an attacker must convince a victim to open a malicious file or interact with attacker-controlled content. Once triggered, the vulnerability provides high impact to confidentiality, integrity, and availability, enabling full code execution within the context of the affected application.

Root Cause

The root cause of CVE-2025-62562 lies in improper memory management within Microsoft Office Outlook's content processing routines. When specific conditions are met during document or email handling, the application fails to properly track the lifetime of allocated memory objects. This results in a dangling pointer scenario where freed memory is subsequently accessed, creating an exploitable condition.

Attack Vector

The attack vector for this vulnerability is local, requiring an attacker to have access to the target system or to socially engineer a user into opening a malicious file. The typical attack scenario involves:

1. An attacker crafts a malicious document, email attachment, or Office file containing exploit code
2. The victim is convinced to open the malicious content through phishing or other social engineering techniques
3. Upon opening, the use-after-free condition is triggered during content processing
4. The attacker's code executes with the privileges of the current user

The vulnerability does not require any elevated privileges from the attacker, making it accessible to low-skilled threat actors once exploit code becomes available. For detailed technical information, refer to the Microsoft Security Update Guide.

Detection Methods for CVE-2025-62562

Indicators of Compromise

• Unexpected crashes or abnormal behavior in Microsoft Office applications, particularly Outlook
• Suspicious Office document files with unusual metadata or embedded objects
• Process memory anomalies or unexpected child processes spawned from Office applications
• Windows Event Log entries indicating application faults in OUTLOOK.EXE or related Office binaries

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions to monitor Office application behavior for memory corruption indicators
• Implement file integrity monitoring on Office installations to detect unauthorized modifications
• Use behavioral analysis to identify anomalous process execution patterns originating from Office applications
• Enable Windows Defender Exploit Guard with Attack Surface Reduction rules for Office applications

Monitoring Recommendations

• Monitor for suspicious Office document downloads or email attachments from untrusted sources
• Enable detailed logging for Office application events and correlate with security information and event management (SIEM) systems
• Track process creation events where Office applications spawn unexpected child processes such as cmd.exe, powershell.exe, or script interpreters
• Review network connections initiated by Office processes for potential command and control communication

How to Mitigate CVE-2025-62562

Immediate Actions Required

• Apply the latest Microsoft security updates for all affected Office products immediately
• Enable Protected View and Office Protected Mode for all document types from untrusted sources
• Implement application control policies to restrict macro execution in Office applications
• Educate users about the risks of opening unsolicited email attachments and documents from unknown sources

Patch Information

Microsoft has released security updates addressing this vulnerability. Organizations should prioritize patching all affected Microsoft Office products, including Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, SharePoint Server, and standalone Word installations. Detailed patch information and download links are available in the Microsoft Security Update Guide for CVE-2025-62562.

Workarounds

• Block Office files containing macros from untrusted sources at the email gateway level
• Configure Microsoft Office to open all documents from the Internet in Protected View
• Disable the Preview Pane in Outlook to prevent automatic rendering of malicious content
• Implement network segmentation to limit lateral movement if exploitation occurs

# Disable macros from the Internet via Group Policy Registry settings
reg add "HKCU\Software\Policies\Microsoft\Office\16.0\Word\Security" /v "blockcontentexecutionfrominternet" /t REG_DWORD /d 1 /f
reg add "HKCU\Software\Policies\Microsoft\Office\16.0\Excel\Security" /v "blockcontentexecutionfrominternet" /t REG_DWORD /d 1 /f
reg add "HKCU\Software\Policies\Microsoft\Office\16.0\Outlook\Security" /v "blockcontentexecutionfrominternet" /t REG_DWORD /d 1 /f