An issue was discovered in Hitachi ID Bravura Security Fabric 11.0.0 through 11.1.3, 12.0.0 through 12.0.2, and 12.1.0. When using federated identity management (authenticating via SAML through a third-party identity provider), an attacker can inject additional data into a signed SAML response being transmitted to the service provider (ID Bravura Security Fabric). The application successfully validates the signed values but uses the unsigned malicious values. An attacker with lower-privilege access to the application can inject the username of a high-privilege user to impersonate that user.