Microsoft has issued a serious warning regarding “active attacks” against its on-premises SharePoint Server software. The company advises that users should assume they have been compromised due to vulnerabilities recently identified. Alongside the FBI and other cybersecurity bodies such as CISA, Microsoft is actively investigating these incidents.

Important Highlights:

• These issues allow attackers to execute unauthorized code and alter network operations.
• SharePoint is widely used in various organizations, including governmental bodies, increasing the potential risk.
• Existing users are urged to apply updates immediately.

CISA noted that the exploitation, termed “ToolShell,” provides unauthorized access to systems which could lead to significant data breaches, including access to internal configurations and file systems. Organizations using SharePoint Subscription Edition should install the designated security updates as soon as possible.

The government and large enterprises relying on on-premises systems are now facing heightened risks, with security experts warning about the extensive implications of such vulnerabilities affecting fundamental server technology.