Symptoms

When running Confluence 3.3.x, users are unable to login when custom SSO is enabled. Prior to upgrading to 3.3.x, the custom SSO worked.

Cause

In Confluence 3.3, we have introduced a new security enhancement called Web Sudo. This enhancement unfortunately is incompatible with some external SSO solutions.

Resolution

1. Start Confluence in Development Mode.
2. Disable 'Secure administrator sessions'. This is located in the 'Security Configuration' page under the 'Security' section, in the Confluence administration panel.
3. Restart Confluence in a normal mode.

Track this improvement request in Custom SSO Fails in Confluence 3.3.x. See Configuring Secure Administrator Sessions for further information.