SAML authentication vulnerability due to stdlib XML parsing
GHSA-w3wf-cfx3-6gcx · CVE-2020-26276
Published · Modified
Description
Impact
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.
Patches
This issue is patched in 3.5.1 using https://github.com/mattermost/xml-roundtrip-validator.
Workarounds
If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet.
References
See https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/ for more information about the underlying vulnerabilities.
For more information
If you have any questions or comments about this advisory:
- Email us at security@fleetdm.com
- Join #fleet in osquery Slack
References
- WEB https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
- ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2020-26276
- WEB https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607
- WEB https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
- WEB https://github.com/mattermost/xml-roundtrip-validator
- WEB https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities
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