Fleet's Windows MDM enrollment process validates Azure AD signed JWTs but fails to check the aud and iss claims. This allows an attacker who can obtain any valid Microsoft Azure AD token with the required scopes to authenticate to Fleet's MDM endpoints. The attacker can enroll unauthorized devices and invoke MDM APIs, potentially exposing sensitive enrollment secrets embedded in command payloads.

All iterations of Fleet before version 4.82.0 running Windows devices with Windows MDM enabled. Fleet v4.81.0 and earlier are vulnerable. The fix was released with version 4.82.0.

The CVSS score of 8.2 indicates a high severity, and the vulnerability is exploitable remotely over the network by anyone who can obtain a suitable Azure AD token. Because the EPSS score is not available and the vulnerability is not in the KEV catalog, the exploitation probability cannot be precisely quantified, but the attack surface is significant as the validation logic is present on the server side. An attacker with access to any Azure AD tenant can perform the exploit without additional privileges.