The chat feature in the Real-Time Collaboration (RTC) services 7.3 and 7.4 in SAP NetWeaver Java AS 7.1 through 7.5 allows remote attackers to obtain sensitive user information by visiting webdynpro/resources/sap.com/tc~rtc~coll.appl.rtc~wd_chat/Chat#, pressing "Add users", and doing a search, aka SAP Security Note 2255990.