Pluto is a superset of Lua 5.4 with a focus on general-purpose programming. Scripts passing user-controlled values to http.request header values are affected. An attacker could use this to send arbitrary requests, potentially leveraging authentication tokens provided in the same headers table.
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.