CVE-2025-21415: Critical Privilege Escalation in Azure AI Face Service

Overview

Microsoft has disclosed a critical vulnerability identified as CVE-2025-21415 in the Azure AI Face Service. This flaw allows for an elevation of privilege through an authentication bypass via spoofing. With a CVSS v3.1 base score of 9.9, the vulnerability poses a significant threat to cloud-based identity and access controls.

What is Azure AI Face Service?

Azure AI Face Service is part of Microsoft’s Cognitive Services platform, enabling facial recognition features such as identity verification, emotion detection, and face grouping. It is widely used in security, access control, and user engagement systems that rely on biometric authentication.

Technical Details

The vulnerability is categorized under CWE-290: Authentication Bypass by Spoofing. This means that an attacker can potentially forge or manipulate identity credentials to gain unauthorized access. In this case, a low-privileged authenticated user can elevate their access rights without direct interaction or additional validation steps.

The CVSS vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H highlights key aspects of the risk:

• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low
• User Interaction: None
• Scope: Changed
• Impact: High on confidentiality, integrity, and availability

Affected Systems

The vulnerability affects the Azure AI Face Service as a whole. Microsoft has not specified particular version numbers, as the service is hosted and maintained within the Azure cloud infrastructure. The issue is exclusive to the cloud-hosted environment and cannot be mitigated by on-premises patching.

Mitigation and Recommendations

Microsoft has addressed the issue via backend updates. There is no manual patch required by customers. However, organizations should:

• Review access logs for suspicious activity
• Audit user roles and privileges
• Ensure applications using Face API enforce additional identity verification layers

According to CISA’s SSVC assessment, the vulnerability has total technical impact, although it is currently not known to be exploited and not automatable.

Conclusion

CVE-2025-21415 emphasizes the importance of secure authentication design, especially in services that manage biometric data. Cloud customers leveraging the Azure AI Face Service should ensure identity access policies are reviewed and monitored frequently. For more details, visit the Microsoft Security Advisory.