Atlassian Confluence versions 3.x and 4.x allow for anonymous users to list all registered users of the system. The vendor does not believe this is a security concern…. Atlassian Confluence versions 3.x and 4.x allow for anonymous users to list all registered users of the system. The vendor does not believe this is a security concern.

Read more http://packetstormsecurity.com/files/122973/atlassianconfluence-disclose.txt