Microsoft SharePoint Under Siege: Unpacking CVE-2025-30378 Deserialization Flaw
Introduction
Microsoft SharePoint, a cornerstone of enterprise collaboration, faces a critical security threat. CVE-2025-30378, a deserialization vulnerability, threatens to compromise systems by enabling unauthorized local code execution. With a CVSS score of 7.0, this vulnerability demands immediate attention from security teams.
Affected Systems and Versions
- Microsoft Office SharePoint (specific affected versions not disclosed in provided materials)
Technical Information
The vulnerability stems from insecure deserialization of untrusted data within SharePoint’s object conversion routines. Attackers with authenticated access exploit this flaw by sending specially crafted serialized payloads to vulnerable endpoints. Upon deserialization, these payloads execute arbitrary code in the context of the SharePoint server’s application pool.
Attack Vectors and Exploitation Methods
Attackers exploit this flaw through authenticated network access, typically leveraging compromised credentials or insider threats. Malicious payloads can be embedded in HTTP requests or uploaded documents, bypassing perimeter defenses and executing arbitrary commands on the server.
Patch Information
Microsoft has released security update KB503787 to address this vulnerability. Organizations must apply this patch immediately via Windows Update or directly from the MSRC portal:
Alternative Mitigations
- Implement strict input validation for serialized data.
- Enforce least-privilege access controls.
- Conduct regular code audits and network segmentation.
Detection Methods
Specific detection methods or Indicators of Compromise (IoCs) for CVE-2025-30378 have not been disclosed in the provided materials.
Vendor Security History
Microsoft has previously addressed similar deserialization vulnerabilities in SharePoint, notably CVE-2021-28474 and CVE-2025-29793. These recurring issues highlight systemic challenges in SharePoint’s data handling architecture, emphasizing the need for proactive security measures.
References
- Microsoft Security Update Guide
- NVD CVE-2025-30378
- Zero Day Initiative May 2025 Security Update Review
Organizations must prioritize patching and mitigation strategies to defend against potential exploitation of CVE-2025-30378, safeguarding critical enterprise collaboration environments.
