Apache Guacamole 1.2.0 and older do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
Acknowledgements: We would like to thank William Le Berre (Synetis) for reporting this issue.