Microsoft fixed actively exploited flaw in Power Pages

Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network

CVE-2025-24989 is a critical (CVSS 9.8) improper access control flaw (CWE-284) in Microsoft Power Pages, Microsoft's low-code cloud service for building external-facing websites. An unauthenticated attacker can trigger it over the network by interacting with an affected Power Pages site, bypassing the user registration control and elevating privileges without any prior credentials or user interaction. Successful exploitation grants elevated access with high impact on the confidentiality, integrity, and availability of the affected site. Only organizations using Power Pages are in scope, and Microsoft has already mitigated the vulnerability in the cloud service and directly notified affected customers - if you were not notified, this vulnerability does not affect you. The flaw was actively exploited before and during patching, was added to CISA's Known Exploited Vulnerabilities catalog on 2025-02-21, and carries a 1.6% EPSS probability of exploitation in the next 30 days.

Do: No customer patch is required because Microsoft applied the fix service-side; review Microsoft's notification and follow its instructions to inspect your Power Pages sites for signs of exploitation (e.g., unexpected or unauthorized users, unusual privilege changes) and perform the recommended cleanup. Federal agencies must apply the vendor mitigations per CISA BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are unavailable. If you were not notified by Microsoft, the vulnerability does not affect you, though reviewing your site's registration settings is a prudent verification step.