Apache Commons FileUpload before 1.5 does not limit the number of request parts to be processed resulting in the possibility of an attacker triggering a DoS with a malicious upload or series of uploads. Note that, like all of the file upload limits, the new configuration option (FileUploadBase#setFileCountMax) is not enabled by default and must be explicitly configured.

Apache Commons FileUpload before 1.3.3 DiskFileItem File Manipulation Remote Code Execution