Microsoft is set to enhance the security framework of its Microsoft 365 suite by phasing out outdated file access methods starting in mid-July 2025. This initiative will disable legacy authentication protocols such as Relying Party Suite (RPS) and FrontPage Remote Procedure Call (FPRPC) across services like SharePoint, OneDrive, and Office applications. These protocols, still in use by some older tools and services to authenticate and open Office files in browsers, are considered vulnerable to phishing and brute-force attacks, failing to meet current security standards.
Once the rollout begins, applications relying on RPS or FPRPC will lose access to files unless they transition to modern authentication methods. Microsoft anticipates completing this transition by August 2025. While no licensing changes are required, organizations must ensure their applications and third-party tools comply with the new authentication standards. Additionally, Microsoft 365 will implement a requirement for administrative approval before any third-party application can access files or connected sites, with IT administrators guided by Microsoft's published instructions.
This update is part of Microsoft's broader Secure Future Initiative (SFI), launched in November 2023, aimed at strengthening security defaults across its products. The SFI focuses on transforming software development with automation and AI, implementing new identity protections, and accelerating vulnerability response. By enforcing modern authentication methods and requiring administrative approvals, Microsoft aims to mitigate security risks associated with legacy protocols and enhance the overall security posture of its services. (microsoft.com)
Organizations are encouraged to proactively assess their current authentication methods and update any applications or services that depend on the deprecated protocols. This proactive approach will ensure uninterrupted access to Microsoft 365 services and contribute to a more secure and resilient digital environment.
Source: Windows Report Microsoft to block outdated file access methods in Microsoft 365 starting July
