A critical vulnerability, identified as CVE-2025-47166, has been discovered in Microsoft SharePoint Server, posing significant security risks to organizations utilizing this platform. This flaw arises from the deserialization of untrusted data, enabling authenticated attackers to execute arbitrary code remotely.
Understanding CVE-2025-47166
CVE-2025-47166 is a remote code execution (RCE) vulnerability affecting Microsoft SharePoint Server. The issue stems from improper handling of serialized objects, allowing attackers to exploit the deserialization process. By crafting malicious payloads, authenticated users can execute arbitrary code within the context of the SharePoint Server, potentially leading to full system compromise.
Technical Details
The vulnerability is classified under CWE-502: Deserialization of Untrusted Data. In this scenario, SharePoint Server fails to adequately validate or sanitize serialized objects received from users. An attacker with appropriate permissions can upload a specially crafted file and trigger its deserialization, leading to code execution on the server.
Affected Versions
While specific affected versions are not detailed in the available sources, similar vulnerabilities have impacted multiple versions of SharePoint Server in the past. For instance, CVE-2024-38023 affected SharePoint Server 2016, 2019, and the Subscription Edition. It is advisable for organizations to consult Microsoft's official advisories to determine the specific versions affected by CVE-2025-47166.
Potential Impact
Exploitation of this vulnerability can have severe consequences, including:
- Unauthorized Access: Attackers can gain control over the SharePoint Server, accessing sensitive information stored within.
- Data Manipulation: Malicious actors may alter or delete critical data, disrupting business operations.
- Malware Deployment: The compromised server can be used to distribute malware to connected systems, expanding the attacker's reach.
- Service Disruption: Attackers can render the SharePoint services unavailable, leading to operational downtime.
To protect against CVE-2025-47166, organizations should implement the following measures:
- Apply Security Updates: Microsoft has released patches addressing this vulnerability. Administrators should prioritize updating all SharePoint Server instances to the latest versions.
- Restrict File Uploads: Limit the ability to upload files to trusted users and implement strict validation checks to prevent malicious files from being uploaded.
- Monitor User Activity: Implement logging and monitoring to detect unusual activities, such as unexpected file uploads or API requests, which may indicate exploitation attempts.
- Enforce Least Privilege Principle: Ensure users have the minimum necessary permissions to perform their tasks, reducing the potential impact of compromised accounts.
- Conduct Regular Security Audits: Perform periodic reviews of system configurations and user permissions to identify and remediate potential security gaps.
CVE-2025-47166 represents a significant threat to organizations relying on Microsoft SharePoint Server for collaboration and document management. By understanding the nature of this vulnerability and implementing recommended mitigation strategies, organizations can enhance their security posture and protect against potential exploits.
Source: MSRC Security Update Guide - Microsoft Security Response Center