Description
Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go's standard library XML parsing, a valid SAML response may be mutated by an attacker to modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue. This issue is patched in 3.5.1. The fix was made using https://github.com/mattermost/xml-roundtrip-validator If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet.
References (5)
Core 5
Core References
Third Party Advisory x_refsource_confirm
https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
Patch, Third Party Advisory x_refsource_misc
https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607
Release Notes, Third Party Advisory x_refsource_misc
https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
Third Party Advisory x_refsource_misc
https://github.com/mattermost/xml-roundtrip-validator
Not Applicable, Third Party Advisory x_refsource_misc
https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities
Scores
CVSS v3
10.0
EPSS
0.0098
EPSS Percentile
76.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Details
CWE
CWE-290
Status
published
Products (2)
fleetdm/fleet
< 3.5.1
fleetdm/fleet
0 - 3.5.1Go
Published
Dec 17, 2020
Tracked Since
Feb 18, 2026