When the resolution Reichert Network Solutions GmbH plugin is used for SSO authentication on Atlassian Jira Server, Atlassian Jira Data Center, Atlassian Confluence Server, Atlassian Confluence Data Center, Atlassian Bitbucket Server, Atlassian Bitbucket Data center, Atlassian Bamboo 5 and Atlassian Bamboo 6, By default, the username/password login page can be accessed by adding the parameter nosso to the login page url which allow to bypass the redirection to an Single Sign-On (SSO) page.
Solution
Review plugin configuration, if not expected this can be disabled in the Addon's configuration's redirection-tab.