diff --git a/lib/rubygems/installer.rb b/lib/rubygems/installer.rb

index ee5fedeb64..a3f9571cf3 100644

--- a/lib/rubygems/installer.rb

+++ b/lib/rubygems/installer.rb

@@ -707,9 +707,26 @@ def verify_gem_home(unpack = false) # :nodoc:

       unpack or File.writable?(gem_home)

   end

-  def verify_spec_name

-    return if spec.name =~ Gem::Specification::VALID_NAME_PATTERN

-    raise Gem::InstallError, "#{spec} has an invalid name"

+  def verify_spec

+    unless spec.name =~ Gem::Specification::VALID_NAME_PATTERN

+      raise Gem::InstallError, "#{spec} has an invalid name"

+    end

+

+    if spec.raw_require_paths.any?{|path| path =~ /\R/ }

+      raise Gem::InstallError, "#{spec} has an invalid require_paths"

+    end

+

+    if spec.extensions.any?{|ext| ext =~ /\R/ }

+      raise Gem::InstallError, "#{spec} has an invalid extensions"

+    end

+

+    if spec.specification_version.to_s =~ /\R/

+      raise Gem::InstallError, "#{spec} has an invalid specification_version"

+    end

+

+    if spec.dependencies.any? {|dep| dep.type =~ /\R/ || dep.name =~ /\R/ }

+      raise Gem::InstallError, "#{spec} has an invalid dependencies"

+    end

   end

   ##

@@ -836,9 +853,11 @@ def dir

   def pre_install_checks

     verify_gem_home options[:unpack]

-    ensure_loadable_spec

+    # The name and require_paths must be verified first, since it could contain

+    # ruby code that would be eval'ed in #ensure_loadable_spec

+    verify_spec

-    verify_spec_name

+    ensure_loadable_spec

     if options[:install_as_default]

       Gem.ensure_default_gem_subdirectories gem_home

diff --git a/test/rubygems/test_gem_installer.rb b/test/rubygems/test_gem_installer.rb

index 93b0482407..7f414d495d 100644

--- a/test/rubygems/test_gem_installer.rb

+++ b/test/rubygems/test_gem_installer.rb

@@ -1474,6 +1474,112 @@ def spec.validate; end

     end

   end

+  def test_pre_install_checks_malicious_name_before_eval

+    spec = util_spec "malicious\n::Object.const_set(:FROM_EVAL, true)#", '1'

+    def spec.full_name # so the spec is buildable

+      "malicious-1"

+    end

+    def spec.validate(*args); end

+

+    util_build_gem spec

+

+    gem = File.join(@gemhome, 'cache', spec.file_name)

+

+    use_ui @ui do

+      @installer = Gem::Installer.at gem

+      e = assert_raises Gem::InstallError do

+        @installer.pre_install_checks

+      end

+      assert_equal "#<Gem::Specification name=malicious\n::Object.const_set(:FROM_EVAL, true)# version=1> has an invalid name", e.message

+    end

+    refute defined?(::Object::FROM_EVAL)

+  end

+

+  def test_pre_install_checks_malicious_require_paths_before_eval

+    spec = util_spec "malicious", '1'

+    def spec.full_name # so the spec is buildable

+      "malicious-1"

+    end

+    def spec.validate(*args); end

+    spec.require_paths = ["malicious\n``"]

+

+    util_build_gem spec

+

+    gem = File.join(@gemhome, 'cache', spec.file_name)

+

+    use_ui @ui do

+      @installer = Gem::Installer.at gem

+      e = assert_raises Gem::InstallError do

+        @installer.pre_install_checks

+      end

+      assert_equal "#<Gem::Specification name=malicious version=1> has an invalid require_paths", e.message

+    end

+  end

+

+  def test_pre_install_checks_malicious_extensions_before_eval

+    spec = util_spec "malicious", '1'

+    def spec.full_name # so the spec is buildable

+      "malicious-1"

+    end

+    def spec.validate(*args); end

+    spec.extensions = ["malicious\n``"]

+

+    util_build_gem spec

+

+    gem = File.join(@gemhome, 'cache', spec.file_name)

+

+    use_ui @ui do

+      @installer = Gem::Installer.at gem

+      e = assert_raises Gem::InstallError do

+        @installer.pre_install_checks

+      end

+      assert_equal "#<Gem::Specification name=malicious version=1> has an invalid extensions", e.message

+    end

+  end

+

+  def test_pre_install_checks_malicious_specification_version_before_eval

+    spec = util_spec "malicious", '1'

+    def spec.full_name # so the spec is buildable

+      "malicious-1"

+    end

+    def spec.validate(*args); end

+    spec.specification_version = "malicious\n``"

+

+    util_build_gem spec

+

+    gem = File.join(@gemhome, 'cache', spec.file_name)

+

+    use_ui @ui do

+      @installer = Gem::Installer.at gem

+      e = assert_raises Gem::InstallError do

+        @installer.pre_install_checks

+      end

+      assert_equal "#<Gem::Specification name=malicious version=1> has an invalid specification_version", e.message

+    end

+  end

+

+  def test_pre_install_checks_malicious_dependencies_before_eval

+    spec = util_spec "malicious", '1'

+    def spec.full_name # so the spec is buildable

+      "malicious-1"

+    end

+    def spec.validate(*args); end

+    spec.add_dependency "b\nfoo", '> 5'

+

+    util_build_gem spec

+

+    gem = File.join(@gemhome, 'cache', spec.file_name)

+

+    use_ui @ui do

+      @installer = Gem::Installer.at gem

+      @installer.ignore_dependencies = true

+      e = assert_raises Gem::InstallError do

+        @installer.pre_install_checks

+      end

+      assert_equal "#<Gem::Specification name=malicious version=1> has an invalid dependencies", e.message

+    end

+  end

+

   def test_shebang

     util_make_exec @spec, "#!/usr/bin/ruby"

-- 

2.21.0