Hummingbird Collaboration (aka Hummingbird Enterprise Collaboration) 5.21 and earlier allows remote attackers to obtain sensitive information (intranet IP addresses and enumerations of valid parameter values) via a direct request to hc, which reveals the information in an error message or a cookie.

Cross-site scripting (XSS) vulnerability in the file manager utility in Hummingbird Collaboration (aka Hummingbird Enterprise Collaboration) 5.21 and earlier allows remote attackers to inject arbitrary web script or HTML in an uploaded page, which is published without a check for hostile scripting.

Hummingbird Collaboration (aka Hummingbird Enterprise Collaboration) 5.21 and earlier allows remote attackers to misrepresent the type and name of a file via modified docext and id parameters, which might trick a user into downloading dangerous or unexpected content.