LDAP authentication bypass in Alerta

In Alerta before version 8.1.0, users may be able to bypass LDAP authentication if they provide an empty password when Alerta server is configure to use LDAP as the authorization provider. Only deployments where LDAP servers are configured to allow unauthenticated authentication mechanism for anonymous authorization are affected. A fix has been implemented in version 8.1.0 that returns HTTP 401 Unauthorized response for any authentication attempts where the password field is empty. As a workaround LDAP administrators can disallow unauthenticated bind requests by clients.