The GiveWP WordPress plugin before 4.16.9 does not remove shortcode delimiters from donor-supplied values before rendering them on public pages, and the shortcode stripping it applies can be defeated by nesting, allowing unauthenticated users to execute arbitrary shortcodes registered on the site.
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.