Fleet before 4.87.0 does not protect the two endpoints that serve in-house iOS application packages and manifests (enterprise tier only) with the intended random, time-limited URL token. Because Apples InstallEnterpriseApplication MDM command requires these URLs to be reachable without a Fleet session, they cannot rely on session-based authentication, and the missing token allows an unauthenticated attacker with network access to the Fleet server to download in-house IPA binaries and their metadata (bundle identifier, version, and name) by guessing sequential title identifiers. The impact is limited to read-only disclosure; there is no privilege escalation or write access, and the free tier is unaffected (it returns fleet.ErrMissingLicense).
Weakness
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.