Checkbox has released an important security update as of April 28, 2021 related to a vulnerability in the respondent-file API method. The update has already been applied to all Checkbox hosted accounts as of April 28. All on-premises customers are encouraged to download and patch to version 7.33.3 as soon as possible.
Additional details on what is included in this update can be found at https://www.checkbox.com/docs/release-notes-version-7-21-0/7-33-2-7-33-3/.
If you have any questions or concerns, please enter a support ticket and we'd be happy to assist.