The MOVEitISAPI service in Ipswitch MOVEit DMZ before 8.2 provides different error messages depending on whether a FileID exists, which allows remote authenticated users to enumerate FileIDs via the X-siLock-FileID parameter in a download action to MOVEitISAPI/MOVEitISAPI.dll.
https://www.profundis-labs.com/advisories/CVE-2015-7677.txt
http://seclists.org/fulldisclosure/2016/Jan/95
http://packetstormsecurity.com/files/135459/Ipswitch-MOVEit-DMZ-8.1-File-ID-Enumeration.html
http://docs.ipswitch.com/MOVEit/DMZ82/ReleaseNotes/MOVEitReleaseNotes82.pdf