VDB
KO
MEDIUM 5.3

GHSA-q9c5-pp7m-fm2g

Fleet: Unauthenticated download of in-house iOS app binaries via predictable URLs

Quick fix

GHSA-q9c5-pp7m-fm2g — github.com/fleetdm/fleet/v4: upgrade to the fixed version with the command below.

go get github.com/fleetdm/fleet/v4@v4.87.0

Details

### Summary

Two endpoints serving in-house iOS application packages and manifests in Fleet's enterprise tier are reachable without a hard-to-guess token in the URL, allowing an unauthenticated attacker who can reach the Fleet server to download an in-house IPA by guessing sequential title identifiers.

### Impact

By design, Apple's `InstallEnterpriseApplication` MDM command requires that the manifest URL be reachable by the managed device without a Fleet session, so these endpoints cannot enforce session-based authentication. Fleet's legacy MDM installer path mitigates this by embedding a random, hard-to-guess token in the URL; the in-house iOS app endpoints (added later) were always intended to use the same time-limited-token pattern but the mitigation was not yet in place.

The result is read-only disclosure of in-house IPA binaries and their metadata (bundle identifier, version, name) that an operator has deployed through Fleet. This is enterprise-tier only — the free tier returns `fleet.ErrMissingLicense`. There is no privilege escalation, write access, or impact on hosts not managed by Fleet.

### Workarounds

If an immediate upgrade is not possible:

- Restrict network access to the Fleet server to trusted networks, as is typical for MDM deployments. - Remove in-house iOS apps that contain sensitive material from Fleet; in-house app IPAs are intentionally reachable by managed devices and should not be relied on as a confidential distribution channel. - Where available, configure CloudFront URL signing for software installers to limit the validity window of issued binary URLs.

### For more information

If you have any questions or comments about this advisory:

Email us at [security@fleetdm.com](mailto:security@fleetdm.com) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)

### Credits

We thank @offset for responsibly reporting this issue.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go / github.com/fleetdm/fleet/v4
Introduced in: 0 Fixed in: 4.87.0
Fix go get github.com/fleetdm/fleet/v4@v4.87.0

References