Sonatype Nexus Repository 3 Pro does not check the local account status when a user signs in through a configured SAML or OAuth2/OpenID Connect identity provider. A user whose account was disabled or locked by an administrator in Nexus Repository can sign in again with valid identity provider credentials for the same account, and then receives a new session with the roles of that account. The attacker needs no Nexus Repository session and no Nexus Repository privilege. The attacker needs a named account that holds valid credentials at the identity provider. The anonymous user is not part of this attack path.
Weak Authentication The product uses an authentication mechanism to restrict access to specific users or identities, but the mechanism does not sufficiently prove that the claimed identity is correct.