GHSA-Q9C5-PP7M-FM2G
Vulnerability from github – Published: 2026-08-20 18:44 – Updated: 2026-08-20 18:44Summary
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 Join #fleet in osquery Slack
Credits
We thank @offset for responsibly reporting this issue.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/fleetdm/fleet/v4"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.87.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-862"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-20T18:44:31Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\n\nTwo endpoints serving in-house iOS application packages and manifests in Fleet\u0027s 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.\n\n### Impact\n\nBy design, Apple\u0027s `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\u0027s 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.\n\nThe 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 \u2014 the free tier returns `fleet.ErrMissingLicense`. There is no privilege escalation, write access, or impact on hosts not managed by Fleet.\n\n### Workarounds\n\nIf an immediate upgrade is not possible:\n\n- Restrict network access to the Fleet server to trusted networks, as is typical for MDM deployments.\n- 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.\n- Where available, configure CloudFront URL signing for software installers to limit the validity window of issued binary URLs.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\nEmail us at [security@fleetdm.com](mailto:security@fleetdm.com)\nJoin #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)\n\n### Credits\n\nWe thank @offset for responsibly reporting this issue.",
"id": "GHSA-q9c5-pp7m-fm2g",
"modified": "2026-08-20T18:44:31Z",
"published": "2026-08-20T18:44:31Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-q9c5-pp7m-fm2g"
},
{
"type": "PACKAGE",
"url": "https://github.com/fleetdm/fleet"
},
{
"type": "WEB",
"url": "https://github.com/fleetdm/fleet/releases/tag/fleet-v4.87.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "Fleet: Unauthenticated download of in-house iOS app binaries via predictable URLs"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.