CVE-2020-26276
SAML authentication vulnerability due to stdlib XML parsing
Impact
### 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](mailto:security@fleetdm.com) * Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/fleetdm/fleet/v4 | < 3.5.1 | 3.5.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Fleetdm | Fleet | before 3.5.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
- https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607
- https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
- https://github.com/mattermost/xml-roundtrip-validator
- https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities
- https://github.com/advisories/GHSA-w3wf-cfx3-6gcx
- https://nvd.nist.gov/vuln/detail/CVE-2020-26276