CVE-2020-26290

Dex is a federated OpenID Connect provider written in Go. In Dex before version 2.27.0 there is a critical set of vulnerabilities which impacts users leveraging the SAML connector. The vulnerabilities enables potential signature bypass due to issues with XML encoding in the underlying Go library. The vulnerabilities have been addressed in version 2.27.0 by using the xml-roundtrip-validator from Mattermost (see related references).

Weakness

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Software

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/463.html
• https://cwe.mitre.org/data/definitions/475.html

References

• https://github.com/dexidp/dex/commit/324b1c886b407594196113a3dbddebe38eecd4e8
• https://github.com/dexidp/dex/releases/tag/v2.27.0
• https://github.com/dexidp/dex/security/advisories/GHSA-m9hp-7r99-94h5
• https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-attributes.md
• https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-directives.md
• https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-elements.md
• https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-q547-gmf8-8jr7
• https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/