This module allows you to configure your Drupal site as a SAML 2.0 Service Provider so that users can authenticate through an external identity provider. The module does not sufficiently prevent reuse of previously accepted SAML assertions. Under certain circumstances, a valid assertion may be replayed within its validity period, potentially allowing repeated authentication attempts using the same assertion. This vulnerability is mitigated by the fact that an attacker must first obtain a valid SAML assertion and can only reuse it during the assertion's validity period.