Install ruby-whitewash by entering the following commands in the terminal:
sudo apt update sudo apt install ruby-whitewash
Description:
Whitelist-based HTML filter for Ruby
This module allows Ruby programs to clean up any HTML document or fragment coming from an untrusted source and to remove all dangerous constructs that could be used for cross-site scripting or request forgery.
Homepage: http://samizdat.nongnu.org/
Version: 2.1-1
Section: universe/ruby