CVE-2021-21296: Denial-of-service in Fleet

Severity: low (CVSS 2.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-02-10 · updated 2026-10-06
Weakness: CWE-400

Description

Fleet is an open source osquery manager. In Fleet before version 3.7.0 a malicious actor with a valid node key can send a badly formatted request that causes the Fleet server to exit, resulting in denial of service. This is possible only while a live query is currently ongoing. We believe the impact of this vulnerability to be low given the requirement that the actor has a valid node key. There is no information disclosure, privilege escalation, or code execution. The issue is fixed in Fleet 3.7.0.

Affected products

fleetdm fleet: before 3.7.0 — fixed in 3.7.0

How to fix

Upgrade to a fixed version: fleetdm fleet 3.7.0. Check the vendor advisory for mitigations.

References

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