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.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26276
Reference (s):
- https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
- URL: https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
- https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
- URL: https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
- https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607