Fleet before 4.87.0 Unauthenticated iOS App Download via Predictable URLs

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 Apple's 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).