CVE-2025-21272: Windows 10 1507 Information Disclosure Flaw

CVE-2025-21272 Overview

CVE-2025-21272 is an information disclosure vulnerability affecting the Windows COM (Component Object Model) Server across a wide range of Microsoft Windows operating systems. This vulnerability allows an authenticated local attacker to potentially read sensitive information from memory, which could be leveraged to gain additional insights into system configurations or facilitate further attacks.

Critical Impact

This vulnerability enables unauthorized disclosure of sensitive information through uninitialized memory access in the Windows COM Server, potentially exposing confidential data to authenticated local attackers.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
• Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, 2025

Discovery Timeline

• January 14, 2025 - CVE-2025-21272 published to NVD
• January 27, 2025 - Last updated in NVD database

Technical Details for CVE-2025-21272

Vulnerability Analysis

This information disclosure vulnerability exists within the Windows COM Server component, a fundamental architectural element of Windows that enables inter-process communication and dynamic object creation. The vulnerability is classified under CWE-908 (Use of Uninitialized Resource), indicating that the COM Server may expose memory contents that have not been properly initialized before use.

The local attack vector means that an attacker must have authenticated access to the target system to exploit this vulnerability. Once exploited, the attacker can potentially read sensitive information that may reside in uninitialized memory regions, including process data, credentials, or other confidential information. The scope is marked as changed, indicating that the vulnerability can affect resources beyond its original security scope, potentially impacting other components or virtual machines on the same host.

Root Cause

The root cause of CVE-2025-21272 lies in improper handling of memory resources within the Windows COM Server. Specifically, the vulnerability stems from the use of uninitialized memory (CWE-908), where memory buffers are allocated but not properly cleared or initialized before being used or returned to calling processes. This can result in sensitive remnant data from previous operations being inadvertently disclosed to unauthorized users or processes.

Attack Vector

An attacker with local access and low-level privileges can exploit this vulnerability without requiring user interaction. The attack involves making specific COM Server requests that trigger the uninitialized memory condition, causing the server to return memory contents that should have been sanitized. Since the vulnerability allows reading confidential data with high impact to confidentiality, attackers could potentially extract sensitive information such as memory addresses, credentials, or cryptographic keys that could be used for further exploitation.

The attack methodology involves:

1. Gaining authenticated local access to the target Windows system
2. Invoking specific COM interfaces or methods that trigger the vulnerable code path
3. Analyzing the returned data for sensitive information disclosure
4. Leveraging disclosed information for subsequent attacks or lateral movement

Detection Methods for CVE-2025-21272

Indicators of Compromise

• Unusual COM Server activity from unexpected user accounts or processes
• Anomalous memory access patterns associated with combase.dll or related COM components
• Unexpected inter-process communication requests targeting COM objects
• Suspicious process behavior attempting to enumerate or interact with multiple COM objects

Detection Strategies

• Monitor for anomalous COM object instantiation patterns, particularly from low-privilege accounts
• Implement endpoint detection rules to identify unusual memory access patterns in COM-related processes
• Enable Windows Event Logging for COM+ events and analyze for suspicious activity
• Deploy behavioral analytics to detect processes attempting to exploit information disclosure vulnerabilities

Monitoring Recommendations

• Enable and review Windows Security Event logs, particularly events related to object access and handle manipulation
• Configure SentinelOne agents to monitor for suspicious COM Server interactions and memory access anomalies
• Implement network segmentation monitoring to detect potential lateral movement following information disclosure
• Establish baseline behavior for COM Server activity to identify deviations indicative of exploitation attempts

How to Mitigate CVE-2025-21272

Immediate Actions Required

• Apply the Microsoft security update addressing CVE-2025-21272 as soon as possible
• Prioritize patching on systems with sensitive data or critical business functions
• Review and restrict local access privileges to minimize the attack surface
• Enable enhanced monitoring on systems where immediate patching is not feasible
• Verify patch deployment across all affected Windows versions in your environment

Patch Information

Microsoft has released security updates to address this vulnerability. Organizations should obtain the appropriate patches from the Microsoft Security Response Center advisory for CVE-2025-21272. The patches are available for all affected Windows versions including Windows 10, Windows 11, and Windows Server editions.

Apply updates through Windows Update, Windows Server Update Services (WSUS), Microsoft Update Catalog, or your enterprise patch management solution. Ensure that systems are rebooted after patch application to complete the remediation process.

Workarounds

• Restrict local login privileges to trusted users and administrative accounts only
• Implement the principle of least privilege to limit the potential impact of exploitation
• Consider application whitelisting to prevent unauthorized processes from interacting with COM objects
• Monitor and audit user access to systems running affected Windows versions until patches can be applied

# Verify Windows COM Server patch status
# Check for installed security updates related to CVE-2025-21272
wmic qfe list full | findstr /i "KB"

# Review COM object access permissions
# Use DCOMCNFG to audit COM security settings
dcomcnfg

# Enable enhanced COM+ event logging
# Navigate to: Event Viewer > Applications and Services Logs > Microsoft > Windows > COM
wevtutil set-log Microsoft-Windows-COM/Analytic /enabled:true