Critical Security Alert: CVE-2025-47163 Threatens Microsoft SharePoint Servers

Microsoft SharePoint Server has recently been identified with a critical security vulnerability, designated as CVE-2025-47163. This flaw arises from the deserialization of untrusted data, potentially allowing authenticated attackers to execute arbitrary code remotely over a network. Given SharePoint's integral role in organizational collaboration and document management, this vulnerability poses a significant risk to enterprises worldwide.

Understanding CVE-2025-47163​

CVE-2025-47163 is a remote code execution (RCE) vulnerability affecting Microsoft SharePoint Server. The issue stems from improper handling of serialized data, enabling attackers with appropriate permissions to exploit the system by uploading maliciously crafted files. Upon deserialization, these files can execute arbitrary code within the context of the SharePoint Server, potentially compromising the entire server environment.

Technical Details​

The vulnerability is classified under CWE-502: Deserialization of Untrusted Data. In this context, deserialization refers to the process of converting serialized data back into its original object form. If this process is not securely implemented, it can be exploited to execute unintended code. In the case of CVE-2025-47163, an attacker with sufficient privileges can upload a specially crafted file to the SharePoint Server. By triggering the deserialization process, the malicious code embedded within the file can be executed, leading to potential system compromise.

Impact and Severity​

The successful exploitation of CVE-2025-47163 can have severe consequences, including:

• Unauthorized Access: Attackers can gain control over the SharePoint Server, accessing sensitive information and potentially escalating privileges within the network.
• Data Manipulation: Malicious actors may alter or delete critical documents, leading to data integrity issues.
• Service Disruption: Execution of arbitrary code can disrupt SharePoint services, causing downtime and affecting business operations.

Given these potential impacts, Microsoft has assigned a high severity rating to this vulnerability.

Affected Versions​

While specific affected versions are not detailed in the available information, it is crucial for organizations using Microsoft SharePoint Server to assess their systems for susceptibility to CVE-2025-47163. Typically, vulnerabilities of this nature affect multiple versions, especially if the underlying deserialization processes are consistent across releases.

Mitigation and Remediation​

To address CVE-2025-47163, Microsoft has released security updates aimed at rectifying the deserialization flaw. Organizations are strongly advised to:

• Apply Security Patches: Ensure that all SharePoint Server instances are updated with the latest security patches provided by Microsoft.
• Restrict File Uploads: Limit the ability to upload files to only trusted and necessary users to reduce the risk of malicious file uploads.
• Monitor User Activity: Implement monitoring mechanisms to detect and log unusual activities related to file uploads and API requests.
• Enforce Least Privilege Principle: Review and adjust user permissions to ensure that individuals have the minimum level of access necessary for their roles.

By implementing these measures, organizations can significantly reduce the risk associated with this vulnerability.

Broader Context: SharePoint Vulnerabilities​

CVE-2025-47163 is part of a series of vulnerabilities identified in Microsoft SharePoint Server over recent years. For instance, in 2024, CVE-2024-38094 was exploited to gain initial access to corporate networks, leading to unauthorized access and potential data breaches. Similarly, CVE-2023-29357 and CVE-2023-24955 were chained together to achieve unauthenticated remote code execution, highlighting the persistent targeting of SharePoint by threat actors. (bleepingcomputer.com, tenable.com)
These incidents underscore the importance of maintaining up-to-date security practices and promptly applying patches to mitigate emerging threats.

Conclusion​

The discovery of CVE-2025-47163 serves as a critical reminder of the vulnerabilities inherent in widely used platforms like Microsoft SharePoint Server. Organizations must remain vigilant, ensuring that security updates are applied promptly and that best practices in access control and monitoring are enforced. By doing so, they can protect their systems against potential exploits and maintain the integrity of their collaborative environments.

---

Source: MSRC Security Update Guide - Microsoft Security Response Center