Hi@all,

there is an information disclosure in OpenXchange (prior 7.8).
An authenticated user can enumerate all imap user folders. If you browse 
the PoC you get an permission denied error, but the folder’s name is 
reflected into the page in json format.

About Open Xchange:
Open-Xchange[2] develops, markets and sells web-based communication, 
collaboration and office productivity software, which enables full 
integration of email, documents, scheduling and social media

Risk-Rating: Very low

PoC:
https://ox.com/appsuite/api/tasks?action=all&folder=10>&columns=6%2C20%2C200%2C202%2C203%2C221%2C300%2C309&sort=202&order=asc&timezone=UTC&session=<YOUR_SESSION>

You have to paste your valid session. The Vulnerable parameter is 
folder. It requires an integer.

The vendor has been informed and fixed the Bug in newest Version.

Best regards

Tim Schughart
IT Security engineer

ProSec Networks
Website: https://www.prosec-networks.com
E-Mail: info@prosec.networks.com
Phone: +49(0) 2621 9469 252