CVE-2025-24989 is a high-severity improper access control vulnerability (CWE-284) found in Microsoft Power Pages, a low-code development platform used to build business websites and portals. The vulnerability allows an unauthorized attacker to elevate privileges over a network by bypassing the user registration control mechanism. This means that an attacker could potentially register or access resources without proper authorization, gaining higher privileges than intended. The vulnerability does not require any user interaction or prior authentication, making it remotely exploitable over the network with low attack complexity. The CVSS 3.1 base score is 8.2, reflecting a high impact on integrity (high) and a limited impact on confidentiality (low) and no impact on availability. The scope remains unchanged, meaning the vulnerability affects only the vulnerable component without impacting other components. Microsoft has already mitigated this vulnerability in their service and notified affected customers, providing instructions for reviewing sites for potential exploitation and cleanup. No known exploits are currently observed in the wild. The vulnerability primarily concerns the bypass of registration controls, which could allow attackers to create unauthorized accounts or escalate privileges, potentially leading to unauthorized data modification or access within affected Power Pages applications.

For European organizations using Microsoft Power Pages, this vulnerability poses a significant risk, especially for those relying on Power Pages for customer-facing portals or internal business applications. Unauthorized privilege escalation could lead to unauthorized access to sensitive business data, manipulation of records, or disruption of business processes. Given the integration of Power Pages with other Microsoft services and data sources, exploitation could also facilitate lateral movement within an organization's cloud environment. This could impact confidentiality and integrity of data, potentially leading to regulatory compliance issues under GDPR if personal data is compromised or altered. The lack of availability impact reduces the risk of service downtime, but the integrity and confidentiality risks remain critical. Organizations in sectors such as finance, healthcare, government, and critical infrastructure in Europe, which often use Microsoft cloud services, could be particularly affected if they have not applied mitigations or reviewed their Power Pages implementations.

European organizations should ensure they have applied all Microsoft patches and updates related to Power Pages, even though Microsoft states the vulnerability has been mitigated in the service. It is critical to review all Power Pages sites for unauthorized user registrations or suspicious privilege escalations, following Microsoft's cleanup instructions. Organizations should audit user registration workflows and access control configurations to confirm that no bypasses remain. Implementing additional monitoring and alerting on unusual registration or privilege escalation activities within Power Pages portals can help detect exploitation attempts early. Restricting network access to Power Pages administration interfaces and enforcing strong authentication and authorization policies can further reduce risk. Organizations should also review integration points between Power Pages and other systems to ensure compromised accounts cannot be leveraged for lateral movement. Finally, conducting a thorough risk assessment and updating incident response plans to include scenarios involving Power Pages privilege escalation will improve preparedness.