Nuclei is a fast and customizable vulnerability scanner based on simple YAML based DSL. In affected versions it a way to execute code template without -code option and signature has been discovered. Some web applications inherit from Nuclei and allow users to edit and execute workflow files. In this case, users can execute arbitrary commands. (Although, as far as I know, most web applications use -t to execute). This issue has been addressed in version 3.3.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.