From: "jeremyevans0 (Jeremy Evans)" <merch-redmine@...>
Date: 2012-05-08T14:34:14+09:00
Subject: [ruby-core:44935] [ruby-trunk - Feature #6409] public_send is easily bypassed


Issue #6409 has been updated by jeremyevans0 (Jeremy Evans).


I see no reason to special case this.  send is a public method, therefore public_send should be allowed to call it.  Attempting to deny access to send for safety reasons is pointless considering that instance_eval is public can be used to work around the issue in the same way:

  t.public_send(:instance_eval, 'secret')
  t.public_send(:instance_eval, 'exec("rm -rf ~")')

public_send doesn't imply safety, at all, and it was not designed for such a purpose.
----------------------------------------
Feature #6409: public_send is easily bypassed
https://bugs.ruby-lang.org/issues/6409#change-26523

Author: postmodern (Hal Brodigan)
Status: Open
Priority: Normal
Assignee: 
Category: core
Target version: 2.0.0


=begin
(({public_send})) can easily be bypassed, by using it to call (({send})). (({public_send})) should explicitly not allow calling (({send})).

    class Test
      private

      def secret
        "top secret"
      end
    end

    t = Test.new

    t.public_send(:secret)
    # => NoMethodError: private method `secret' called for #<Test:0x0000000159b950>

    t.public_send(:send, :secret)
    # => "top secret"

    t.public_send(:send, :exec, "rm -rf ~")
=end


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