From cdf1b85ae79cd4fe3995a72b6b861d8eb2a9d664 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 20 Dec 2017 04:25:01 +0000
Subject: [PATCH] Fixed command Injection

* lib/resolv.rb (Resolv::Config.parse_resolv_conf): fixed
  potential command injection by use of Kernel#open.
  [ruby-core:84347] [Bug #14205]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61351 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/resolv.rb            |  2 +-
 test/resolv/test_addr.rb | 11 +++++++++++
 test/resolv/test_dns.rb  | 10 ++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lib/resolv.rb b/lib/resolv.rb
index 56183b837d..48ee400efe 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -928,7 +928,7 @@ class Resolv
         nameserver = []
         search = nil
         ndots = 1
-        open(filename, 'rb') {|f|
+        File.open(filename, 'rb') {|f|
           f.each {|line|
             line.sub!(/[#;].*/, '')
             keyword, *args = line.split(/\s+/)
diff --git a/test/resolv/test_addr.rb b/test/resolv/test_addr.rb
index 4a2df5bfca..78a28c9633 100644
--- a/test/resolv/test_addr.rb
+++ b/test/resolv/test_addr.rb
@@ -27,4 +27,15 @@ class TestResolvAddr < Test::Unit::TestCase
       end
     end
   end
+
+  def test_hosts_by_command
+    Dir.mktmpdir do |dir|
+      Dir.chdir(dir) do
+        hosts = Resolv::Hosts.new("|echo error")
+        assert_raise(Errno::ENOENT) do
+          hosts.each_name("") {}
+        end
+      end
+    end
+  end
 end
diff --git a/test/resolv/test_dns.rb b/test/resolv/test_dns.rb
index f21a094b20..8236078374 100644
--- a/test/resolv/test_dns.rb
+++ b/test/resolv/test_dns.rb
@@ -179,6 +179,16 @@ class TestResolvDNS < Test::Unit::TestCase
     end
   end
 
+  def test_resolv_conf_by_command
+    Dir.mktmpdir do |dir|
+      Dir.chdir(dir) do
+        assert_raise(Errno::ENOENT) do
+          Resolv::DNS::Config.parse_resolv_conf("|echo foo")
+        end
+      end
+    end
+  end
+
   def test_dots_diffences
     name1 = Resolv::DNS::Name.create("example.org")
     name2 = Resolv::DNS::Name.create("ex.ampl.eo.rg")