# ©AngelaMos | 2026
# exploit_probe.rb

require "rube"

CANARY_PATH = "/tmp/rube-canary"
CANARY_MARKER = "fired"
RESULT_FIRED = "FIRED"
RESULT_BLOCKED = "BLOCKED"
RESULT_INERT = "INERT"

erb_version = Gem::Specification.find_all_by_name("erb").map(&:version).max.to_s
chain = Rube::Chains::ErbDefMethod.canary(CANARY_PATH, CANARY_MARKER)
blob = chain.serialize

inspection = Rube::Marshal::Parser.new(blob).parse

File.delete(CANARY_PATH) if File.exist?(CANARY_PATH)

revived = Marshal.load(blob)
detail = begin
  revived.def_method(Module.new, "rube_probe")
  "def_method returned"
rescue StandardError => e
  "#{e.class}: #{e.message}"
end

fired = File.exist?(CANARY_PATH) && File.read(CANARY_PATH) == CANARY_MARKER
outcome = if fired
            RESULT_FIRED
          elsif detail.start_with?("ArgumentError")
            RESULT_BLOCKED
          else
            RESULT_INERT
          end

predicted = Rube::Chains::ErbDefMethod.affects?(erb_version) ? RESULT_FIRED : RESULT_BLOCKED

puts format("%-9s erb=%-9s outcome=%-8s predicted=%-8s classes=%-6s %s",
            ENV.fetch("MATRIX_IMAGE", "?"), erb_version, outcome, predicted,
            inspection.class_names.join(","), detail)

exit(outcome == predicted ? 0 : 1)