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Multiple vulnerabilities in Microsoft SharePoint Server 

Indian – Computer Emergency Response Team (https://www.cert-in.org.in)

Severity Rating: CRITICAL

Software Affected

Microsoft SharePoint Server Subscription Edition (on‑premises)

Microsoft SharePoint Server 2019

Microsoft SharePoint Enterprise Server 2016 (all versions prior to July 21, 2025)

Overview

Multiple vulnerabilities have been reported in Microsoft SharePoint Server, which could be exploited by a remote attacker to execute arbitrary code, access sensitive data, or perform spoofing attacks on the targeted system.

Target Audience:

All end-user organizations and individuals using affected Microsoft SharePoint Server installations.

Risk Assessment:

High risk of unauthorized access to sensitive data, remote code execution, and potential disruption of services.

Impact Assessment:

Potential for unauthorized access to sensitive information, execution of arbitrary code, privilege escalation, and full system compromise.

Description

Microsoft SharePoint is a web-based collaboration and document management platform developed by Microsoft. It enables organizations to create, manage, and share content, knowledge, and applications in a centralized, secure environment.

Multiple vulnerabilities exist in Microsoft SharePoint Server due to deserialization of untrusted data in on-premises versions and improper limitation of a pathname to a restricted directory (‘path traversal’).

A remote attacker could exploit these vulnerabilities by sending specially crafted requests to the targeted system. Successful exploitation of these vulnerabilities could allow an attacker to execute arbitrary code, access sensitive data, or perform spoofing attacks on the targeted system.

Note: CVE-2025-53770 is being actively exploited in the wild.

Solution

Apply the security updates released by Microsoft to address these vulnerabilities:

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771

Mitigation Measures

Apply the latest security patches for Microsoft SharePoint Server as per the above advisories.

Rotate the ASP.NET MachineKey values (ValidationKey and DecryptionKey) after applying the updates to invalidate any compromised credentials.

Enable AMSI (Antimalware Scan Interface) integration in SharePoint to enhance detection of malicious activity.

Deploy Microsoft Defender Antivirus or a compatible endpoint protection solution with updated signatures.

Scan SharePoint directories (e.g., LAYOUTS folder) for unauthorized ASPX files such as spinstall0.aspx.

Monitor systems for suspicious process activity such as w3wp.exe spawning cmd.exe or powershell.exe.

Restrict external access to on-premises SharePoint servers where feasible until patched.

Review logs for signs of exploitation and conduct a thorough compromise assessment if any indicators are found.

Vendor Information

Microsoft

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771

References

 

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771

CVE Name

CVE-2025-53770

CVE-2025-53771

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Thanks and Regards,

CERT-In

Incident Response Help Desk

e-mail: incident@cert-in.org.in

Phone: +91-11-22902657

Toll Free Number: 1800-11-4949

Toll Free Fax : 1800-11-6969

Web: http://www.cert-in.org.in

PGP Fingerprint: A768 083E 4475 5725 B81A A379 2156 C0C0 B620 D0B4

PGP Key information:

https://www.cert-in.org.in/s2cMainServlet?pageid=CONTACTUS

Postal address:

Indian Computer Emergency Response Team (CERT-In)

Ministry of Electronics and Information Technology

Government of India

Electronics Niketan

6, C.G.O. Complex

New Delhi-110 003

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