### Summary A vulnerability in Fleet's Windows MDM enrollment flow allows authentication tokens from any Azure AD tenant to be accepted. Because Fleet validates JWT signatures using Microsoft's multi-tenant JWKS endpoint but does not enforce the `aud` (audience) or `iss` (issuer) claims, any Microsoft-signed Azure AD access token containing the expected scopes can be used to authenticate to Fleet's MDM endpoints. ### Impact If Windows MDM is enabled, an attacker with access to any Azure AD tenant can obtain a valid Microsoft-signed token and use it to enroll unauthorized devices and interact with Fleet's MDM management APIs. During device management, Fleet may expose sensitive enrollment secrets embedded in MDM command payloads, enabling further unauthorized access. ### Workarounds If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM. ### For more information If you have any questions or comments about this advisory: Email us at [[email protected]](mailto:[email protected]) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw) ### Credits We thank @zaddy6 for responsibly reporting this issue.
### Summary A vulnerability in Fleet's Windows MDM enrollment flow allows authentication tokens from any Azure AD tenant to be accepted. Because Fleet validates JWT signatures using Microsoft's multi-tenant JWKS endpoint but does not enforce the `aud` (audience) or `iss` (issuer) claims, any Microsoft-signed Azure AD access token containing the expected scopes can be used to authenticate to Fleet's MDM endpoints. ### Impact If Windows MDM is enabled, an attacker with access to any Azure AD tenant can obtain a valid Microsoft-signed token and use it to enroll unauthorized devices and interact with Fleet's MDM management APIs. During device management, Fleet may expose sensitive enrollment secrets embedded in MDM command payloads, enabling further unauthorized access. ### Workarounds If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM. ### For more information If you have any questions or comments about this advisory: Email us at [[email protected]](mailto:[email protected]) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw) ### Credits We thank @zaddy6 for responsibly reporting this issue.
Update github.com/fleetdm/fleet/v4 to 4.82.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanFleet Windows MDM Azure AD JWT Authentication Bypass affects github.com/fleetdm/fleet/v4 (go). Severity is high. ### Summary A vulnerability in Fleet's Windows MDM enrollment flow allows authentication tokens from any Azure AD tenant to be accepted. Because Fleet validates JWT signatures using Microsoft's multi-tenant JWKS endpoint but does not enforce the `aud` (audience) or `iss` (issuer) claims, any Microsoft-signed Azure AD access token containing the expected scopes can be used to authenticate to Fleet's MDM endpoints. ### Impact If Windows MDM is enabled, an attacker with access to any Azure AD tenant can obtain a valid Microsoft-signed token and use it to enroll unauthorized devices and interact with Fleet's MDM management APIs. During device management, Fleet may expose sensitive enrollment secrets embedded in MDM command payloads, enabling further unauthorized access. ### Workarounds If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM. ### For more information If you have any questions or comments about this advisory: Email us at [[email protected]](mailto:[email protected]) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw) ### Credits We thank @zaddy6 for responsibly reporting this issue.
AI coding agents often install or upgrade packages automatically in go. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| github.com/fleetdm/fleet/v4go | <4.82.0 | 4.82.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate github.com/fleetdm/fleet/v4 to 4.82.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanFleet Windows MDM Azure AD JWT Authentication Bypass affects github.com/fleetdm/fleet/v4 (go). Severity is high. ### Summary A vulnerability in Fleet's Windows MDM enrollment flow allows authentication tokens from any Azure AD tenant to be accepted. Because Fleet validates JWT signatures using Microsoft's multi-tenant JWKS endpoint but does not enforce the `aud` (audience) or `iss` (issuer) claims, any Microsoft-signed Azure AD access token containing the expected scopes can be used to authenticate to Fleet's MDM endpoints. ### Impact If Windows MDM is enabled, an attacker with access to any Azure AD tenant can obtain a valid Microsoft-signed token and use it to enroll unauthorized devices and interact with Fleet's MDM management APIs. During device management, Fleet may expose sensitive enrollment secrets embedded in MDM command payloads, enabling further unauthorized access. ### Workarounds If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM. ### For more information If you have any questions or comments about this advisory: Email us at [[email protected]](mailto:[email protected]) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw) ### Credits We thank @zaddy6 for responsibly reporting this issue.
AI coding agents often install or upgrade packages automatically in go. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| github.com/fleetdm/fleet/v4go | <4.82.0 | 4.82.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard