CVE-2025-53772: Microsoft Web Deploy 4.0 RCE Vulnerability

CVE-2025-53772 Overview

CVE-2025-53772 is an insecure deserialization vulnerability affecting Microsoft Web Deploy 4.0. This vulnerability allows an authorized attacker to execute arbitrary code over a network by exploiting the improper handling of untrusted serialized data. Deserialization vulnerabilities (CWE-502) occur when an application deserializes data from untrusted sources without proper validation, allowing attackers to manipulate the serialized objects to achieve malicious outcomes such as remote code execution.

Critical Impact

An authenticated attacker can leverage this deserialization flaw to execute arbitrary code on affected systems, potentially leading to complete system compromise, data exfiltration, and lateral movement within enterprise environments.

Affected Products

• Microsoft Web Deploy 4.0

Discovery Timeline

• 2025-08-12 - CVE-2025-53772 published to NVD
• 2025-08-15 - Last updated in NVD database

Technical Details for CVE-2025-53772

Vulnerability Analysis

This vulnerability stems from improper handling of deserialization operations within Microsoft Web Deploy 4.0. When an application deserializes data without adequate validation, an attacker who has authorization to interact with the affected component can craft malicious serialized objects that, when processed, result in arbitrary code execution on the target system.

The attack can be conducted over the network, requires low complexity to exploit, and does not require user interaction. While the attacker needs to be authorized (low privileges required), successful exploitation grants the ability to execute code with the privileges of the Web Deploy service, potentially impacting confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2025-53772 is the insecure deserialization of untrusted data (CWE-502). Microsoft Web Deploy 4.0 processes serialized data without sufficiently validating its contents or structure before deserialization. This allows attackers to inject malicious object graphs that execute arbitrary code during the deserialization process.

In .NET environments, insecure deserialization commonly occurs when using formatters like BinaryFormatter, SoapFormatter, or ObjectStateFormatter without proper type validation. Attackers can leverage gadget chains—sequences of existing code that, when combined through deserialization, achieve unintended functionality such as command execution.

Attack Vector

The attack vector for this vulnerability is network-based. An authorized attacker can exploit this flaw by sending specially crafted serialized payloads to the vulnerable Web Deploy service. The attack flow typically involves:

1. The attacker identifies a Web Deploy endpoint accepting serialized data
2. A malicious serialized payload is constructed containing a gadget chain targeting known .NET deserialization vulnerabilities
3. The payload is transmitted to the target over the network
4. When the Web Deploy service deserializes the untrusted data, the malicious object graph is instantiated
5. Code execution occurs within the context of the Web Deploy service

The vulnerability mechanism exploits the inherent trust placed in serialized object streams. When deserialization occurs without type filtering or input validation, the runtime instantiates objects and invokes methods specified in the serialized data, allowing attackers to hijack execution flow. For detailed technical information, refer to the Microsoft Security Advisory.

Detection Methods for CVE-2025-53772

Indicators of Compromise

• Unusual network traffic patterns to Web Deploy service endpoints, particularly large or malformed payloads
• Unexpected process spawning from Web Deploy-related processes (msdeploy.exe, MsDepSvc.exe)
• Anomalous file system activity or registry modifications initiated by Web Deploy services
• Error logs indicating deserialization failures or type instantiation errors

Detection Strategies

• Monitor network traffic for suspicious serialized payloads targeting Web Deploy endpoints
• Implement endpoint detection rules to identify known .NET deserialization gadget chain patterns
• Deploy application-layer firewalls capable of inspecting and blocking malicious serialized data
• Enable detailed logging on Web Deploy services and correlate with SIEM solutions for anomaly detection

Monitoring Recommendations

• Configure Windows Event Logging to capture Web Deploy service activities and errors
• Implement process monitoring to detect unusual child processes spawned by Web Deploy components
• Monitor for outbound connections from Web Deploy services that may indicate post-exploitation activity
• Regularly review access logs for Web Deploy endpoints to identify unauthorized or suspicious authentication attempts

How to Mitigate CVE-2025-53772

Immediate Actions Required

• Apply the security patch provided by Microsoft as soon as possible
• Restrict network access to Web Deploy services to trusted IP ranges only
• Review and limit user privileges for Web Deploy operations to minimize the attack surface
• Consider temporarily disabling Web Deploy services in production environments until patching is complete

Patch Information

Microsoft has released a security update addressing CVE-2025-53772. Organizations should consult the Microsoft Security Update Guide for detailed patch information and apply the recommended updates to all affected Microsoft Web Deploy 4.0 installations.

Ensure that all instances of Web Deploy are updated and verify the installation through Windows Update or manual deployment of the security patch.

Workarounds

• Implement network segmentation to isolate Web Deploy services from untrusted networks
• Configure firewall rules to restrict access to Web Deploy endpoints from authorized sources only
• Enable authentication and use strong credentials for all Web Deploy operations
• Consider using alternative deployment mechanisms until the patch can be applied

# Example: Restrict Web Deploy service access via Windows Firewall
netsh advfirewall firewall add rule name="Block Web Deploy External" dir=in action=block program="%ProgramFiles%\IIS\Microsoft Web Deploy V3\msdeploy.exe" remoteip=any
netsh advfirewall firewall add rule name="Allow Web Deploy Trusted" dir=in action=allow program="%ProgramFiles%\IIS\Microsoft Web Deploy V3\msdeploy.exe" remoteip=10.0.0.0/8,192.168.0.0/16