Description

Spring Security versions 5.2.x prior to 5.2.4 and 5.3.x prior to 5.3.2 contain a signature wrapping vulnerability during SAML response validation. When using the spring-security-saml2-service-provider component, a malicious user can carefully modify an otherwise valid SAML response and append an arbitrary assertion that Spring Security will accept as valid.

Affected Spring Products and Versions

• Spring Security
  • 5.2.x prior to 5.2.4
  • 5.3.x prior to 5.3.2

Mitigation

• Spring Security
  • 5.2.4
  • 5.3.2

Credit

This issue was identified and responsibly reported by Sam Tinklenberg.

References

• https://github.com/spring-projects/spring-security/tree/5.2.3.RELEASE/samples/boot/saml2login
• https://docs.spring.io/spring-security/site/docs/5.2.3.RELEASE/reference/html5/#saml2

History

• 2020-05-07: Initial vulnerability report published.