On July 21, 2025, a critical security vulnerability identified as CVE-2025-53770 was declared on Microsoft SharePoint Server. The vulnerability impacted any on-premise SharePoint Server installs. This vulnerability allows unauthenticated attackers to execute remote code via unsafe deserialization and allows attackers to load arbitrary code without user interaction. There is a second vulnerability associated with this research that will elevate the structural deficits that will lead to the risk of imminent compromise of a complete SharePoint server, CVE-2025-53771. The vulnerability is already being exploited, prompting Microsoft to release out-of-band security patches for SharePoint Server Subscription Edition and SharePoint 2019. Technical patches for legacy apps such as SharePoint 2016 are currently being developed. According to Microsoft, the risk is real.
Even though patches were released relatively quickly, the adversarial landscape has advanced further and formal tooling known as “ToolShell” has been developed for exploitations that can bypass internal deterrents and elevate the threat in on-premise SharePoint environments. Organizations that are unable to expeditiously implement the suggested telemetry for malware protection, such as enabling the Microsoft Antimalware Scan Interface (AMSI), should disconnect vulnerable servers from the Internet.
Why On-Premises SharePoint Servers are Risky Now
The ongoing exploitation of these critical vulnerabilities indicates the elevated threat level that on-premises SharePoint servers currently face. As attacks evolve, it also shows that just patching may not offer comprehensive protection of these environments from sophisticated attacker behaviours and creative security bypasses.
Migrate Your SharePoint to the Secure Cloud Platform
The best way to effectively protect your enterprise content and maintain business continuity is to migrate all SharePoint workloads to Microsoft 365’s secure cloud platform, which is unaffected by these vulnerabilities and has continuous security updates and integrated threat intelligence from Microsoft’s cloud system and secure protections from Microsoft’s infrastructure.
Migration Tools to Simplify Your Journey
Organizations ready to migrate have access to several powerful migration tools that streamline and automate the transition process:
- ShareGate Desktop: ShareGate Desktop is a user-friendly migration tool that has bulk migration features that allow for the effective, efficient, and accurate transfer of a significant amount of content. ShareGate has advanced features to assist with permissions management to ensure access controls remain secure throughout the migration. ShareGate has extensive reporting features to monitor the status of migrations to have the information needed to anticipate and resolve issues when they arise.
- Matrix: Metalogix Content Matrix is a tool designed for complex SharePoint environments that demand sophisticated approaches to managing content and metadata. It provides a simplified approach to managing complex SharePoint structure while ensuring important metadata is migrated.
- Microsoft SharePoint Migration Tool (SPMT): Microsoft SharePoint Migration Tool (SPMT) is a free Microsoft tool that allows for quick, reliable content migration to SharePoint Online and OneDrive. If your migration is simple, SPMT is an excellent alternative option that is cost-effective. SPMT provides the ability to perform incremental migrations and decreases both the impact to the inactive time of the dataset and data transfer policy.
One Critical Step to Solve This Error
Enable Microsoft Antimalware Scan Interface (AMSI) immediately on your on-premises SharePoint servers. AMSI is a vital component that adds yet another layer of protection to your environment as it provides real-time scanning of scripts and other content for malware signatures, preventing malicious code exploit attempts to execute such as CVE-2025-53770. Enabling AMSI protects your organization from attackers successfully exploiting dangerous deserialization vulnerabilities while migrating or patching their environments.
Peafowl IT Solution will take several specific security steps during your SharePoint migration:
- Conduct a baseline pre-migration security assessment to identify the organization’s sensitive data and review current permissions and access controls in place.
- Encrypt all current data at rest, as well as the data in transit, to ensure data transferred meets secure protocols (SSL/TLS).
- Maintain strict access controls allowing only authorized users to handle associated migration tools, tasks and sensitive enterprise information.
- Implement and conform to role-based access management and map and validate access permissions prior to migration, and again in the new environment, to ensure only authorized personnel can access the enterprise data.
- Enable comprehensive auditing and logging of activities done during the migration; to provide a full audit trail, including log preservation for compliance and for future change clarity.
- Conduct pilot runs of the migration to validate migrating clean data, and ensure the data remains intact with thorough data validation, limited invalid data at an acceptable level before migration, and protect against data leakage or information loss during the migration process.
- Use Multi-Factor Authentication (MFA) for migrations. Relay expectations to the end-users for recognising and avoiding phishing-roguery during transitions and changes.
- In addition to post migration validation of permissions, identify, confirm and verify workflows and content. Where needed, be prepared to revert your company data over to its previous state until you are able to rebuild with maximum protection.
Following these protocols provides comprehensive enterprise protection, maintains regulatory compliance, and precedence to a seamless transition to Microsoft 365.
Partner with Peafowl IT Solution for Your SharePoint Migration Needs
Peafowl IT Solution specializes in seamless migration from vulnerable on-premises SharePoint servers to the secure, scalable Microsoft 365 cloud platform. Our SharePoint development experts minimizes downtime, addresses emerging security needs, and streamlines your IT ecosystem for a future-proof SharePoint environment. We offer comprehensive migration consultation and provide a free estimation tailored to your requirements.
Contact Peafowl IT Solution today to receive expert guidance, plan your SharePoint migration, and safeguard your enterprise with a smooth, secure transition.
