CVE-2014-0156 (published 2022-06-30T21:15Z)

Awesome spawn contains OS command injection vulnerability, which allows execution of additional commands passed to Awesome spawn as arguments. If untrusted input was included in command arguments, attacker could use this flaw to execute arbitrary command.

Severity: HIGH
CVSS v2 base score: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.8, CRITICAL (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-78
cwe_name: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
description: The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
extended_description: 
		   This weakness can lead to a vulnerability in environments in which the attacker does not have direct access to the operating system, such as in web applications. Alternately, if the weakness occurs in a privileged program, it could allow the attacker to specify commands that normally would not be accessible, or to call alternate commands with privileges that the attacker does not have. The problem is exacerbated if the compromised process does not follow the principle of least privilege, because the attacker-controlled commands may run with special system privileges that increases the amount of damage.
            There are at least two subtypes of OS command injection:
               
				 The application intends to execute a single, fixed program that is under its own control. It intends to use externally-supplied inputs as arguments to that program. For example, the program might use system("nslookup [HOSTNAME]") to run nslookup and allow the user to supply a HOSTNAME, which is used as an argument. Attackers cannot prevent nslookup from executing. However, if the program does not remove command separators from the HOSTNAME argument, attackers could place the separators into the arguments, which allows them to execute their own program after nslookup has finished executing.
				 The application accepts an input that it uses to fully select which program to run, as well as which commands to use. The application simply redirects this entire command to the operating system. For example, the program might use "exec([COMMAND])" to execute the [COMMAND] that was supplied by the user. If the COMMAND is under attacker control, then the attacker can execute arbitrary commands or programs. If the command is being executed using functions like exec() and CreateProcess(), the attacker might not be able to combine multiple commands together in the same line.
               
            From a weakness standpoint, these variants represent distinct programmer errors. In the first variant, the programmer clearly intends that input from untrusted parties will be part of the arguments in the command to be executed. In the second variant, the programmer does not intend for the command to be accessible to any untrusted party, but the programmer probably has not accounted for alternate ways in which malicious attackers can provide input.
         
         

Fix information:
repo_url: https://github.com/ManageIQ/awesome_spawn
commit_details: repo_url: https://github.com/ManageIQ/awesome_spawn
author: Jason Frey
author_date: 2014-06-07 17:01:21-04:00
msg: Separate command line building and sanitizing into its own class.
repository: repo_url: https://github.com/ManageIQ/awesome_spawn
repo_name: ManageIQ/awesome_spawn
description: AwesomeSpawn is a module that provides some useful features over Ruby's Kernel.spawn.
repo_language: Ruby
owner: ManageIQ
file_changes: filename: awesome_spawn.rb
change_type: ModificationType.MODIFY
diff: @@ -1,9 +1,9 @@
 require "awesome_spawn/version"
+require "awesome_spawn/command_line_builder"
 require "awesome_spawn/command_result"
 require "awesome_spawn/command_result_error"
 require "awesome_spawn/no_such_file_error"
 
-require "shellwords"
 require "open3"
 
 module AwesomeSpawn
@@ -100,60 +100,13 @@ module AwesomeSpawn
     command_result
   end
 
-  # Build the full command line.
-  #
-  # @param [String] command The command to run
-  # @param [Hash,Array] params Optional command line parameters. They can
-  #   be passed as a Hash or associative Array. The values are sanitized to
-  #   prevent command line injection.  Keys as symbols are prefixed with `--`,
-  #   and `_` is replaced with `-`.
-  #
-  #   - `{:key => "value"}`            generates `--key value`
-  #   - `{"--key" => "value"}`         generates `--key value`
-  #   - `{:key= => "value"}`           generates `--key=value`
-  #   - `{"--key=" => "value"}`        generates `--key=value`
-  #   - `{:key_name => "value"}`       generates `--key-name value`
-  #   - `{:key => nil}`                generates `--key`
-  #   - `{"-f" => ["file1", "file2"]}` generates `-f file1 file2`
-  #   - `{nil => ["file1", "file2"]}`  generates `file1 file2`
-  #
-  # @return [String] The full command line
+  # (see CommandLineBuilder#build)
   def build_command_line(command, params = nil)
-    return command.to_s if params.nil? || params.empty?
-    "#{command} #{assemble_params(sanitize(params))}"
+    CommandLineBuilder.new.build(command, params)
   end
 
   private
 
-  def sanitize(params)
-    return [] if params.nil? || params.empty?
-    params.collect do |k, v|
-      [sanitize_key(k), sanitize_value(v)]
-    end
-  end
-
-  def sanitize_key(key)
-    case key
-    when Symbol then "--#{key.to_s.tr("_", "-")}"
-    else             key
-    end
-  end
-
-  def sanitize_value(value)
-    case value
-    when Array    then value.collect { |i| i.to_s.shellescape }
-    when NilClass then value
-    else               value.to_s.shellescape
-    end
-  end
-
-  def assemble_params(sanitized_params)
-    sanitized_params.collect do |pair|
-      pair_joiner = pair.first.to_s.end_with?("=") ? "" : " "
-      pair.flatten.compact.join(pair_joiner)
-    end.join(" ")
-  end
-
   def launch(command, in_data, spawn_options = {})
     spawn_options = spawn_options.merge(:stdin_data => in_data) if in_data
     output, error, status = Open3.capture3(command, spawn_options)

programming_language: Ruby
filename: command_line_builder.rb
change_type: ModificationType.ADD
diff: @@ -0,0 +1,59 @@
+require "shellwords"
+
+module AwesomeSpawn
+  class CommandLineBuilder
+    # Build the full command line.
+    #
+    # @param [String] command The command to run
+    # @param [Hash,Array] params Optional command line parameters. They can
+    #   be passed as a Hash or associative Array. The values are sanitized to
+    #   prevent command line injection.  Keys as symbols are prefixed with `--`,
+    #   and `_` is replaced with `-`.
+    #
+    #   - `{:key => "value"}`            generates `--key value`
+    #   - `{"--key" => "value"}`         generates `--key value`
+    #   - `{:key= => "value"}`           generates `--key=value`
+    #   - `{"--key=" => "value"}`        generates `--key=value`
+    #   - `{:key_name => "value"}`       generates `--key-name value`
+    #   - `{:key => nil}`                generates `--key`
+    #   - `{"-f" => ["file1", "file2"]}` generates `-f file1 file2`
+    #   - `{nil => ["file1", "file2"]}`  generates `file1 file2`
+    #
+    # @return [String] The full command line
+    def build(command, params = nil)
+      return command.to_s if params.nil? || params.empty?
+      "#{command} #{assemble_params(sanitize(params))}"
+    end
+
+    private
+
+    def sanitize(params)
+      return [] if params.nil? || params.empty?
+      params.collect do |k, v|
+        [sanitize_key(k), sanitize_value(v)]
+      end
+    end
+
+    def sanitize_key(key)
+      case key
+      when Symbol then "--#{key.to_s.tr("_", "-")}"
+      else             key
+      end
+    end
+
+    def sanitize_value(value)
+      case value
+      when Array    then value.collect { |i| i.to_s.shellescape }
+      when NilClass then value
+      else               value.to_s.shellescape
+      end
+    end
+
+    def assemble_params(sanitized_params)
+      sanitized_params.collect do |pair|
+        pair_joiner = pair.first.to_s.end_with?("=") ? "" : " "
+        pair.flatten.compact.join(pair_joiner)
+      end.join(" ")
+    end
+  end
+end

programming_language: Ruby
filename: awesome_spawn_spec.rb
change_type: ModificationType.MODIFY
diff: @@ -128,71 +128,4 @@ describe AwesomeSpawn do
       let(:run_method) {"run!"}
     end
   end
-
-  context ".build_command_line" do
-    it "sanitizes crazy params" do
-      cl = subject.build_command_line("true", modified_params)
-      expect(cl).to eq "true --user bob --pass P@\\$sw0\\^\\&\\ \\|\\<\\>/-\\+\\*d\\% --db --desc=Some\\ Description --symkey --symkey-dash pkg1 some\\ pkg --pool 123 --pool 456"
-    end
-
-    it "handles Symbol keys" do
-      cl = subject.build_command_line("true", :abc => "def")
-      expect(cl).to eq "true --abc def"
-    end
-
-    it "handles Symbol keys with tailing '='" do
-      cl = subject.build_command_line("true", :abc= => "def")
-      expect(cl).to eq "true --abc=def"
-    end
-
-    it "handles Symbol keys with underscore" do
-      cl = subject.build_command_line("true", :abc_def => "ghi")
-      expect(cl).to eq "true --abc-def ghi"
-    end
-
-    it "handles Symbol keys with underscore and tailing '='" do
-      cl = subject.build_command_line("true", :abc_def= => "ghi")
-      expect(cl).to eq "true --abc-def=ghi"
-    end
-
-    it "sanitizes Fixnum array param value" do
-      cl = subject.build_command_line("true", nil => [1])
-      expect(cl).to eq "true 1"
-    end
-
-    it "sanitizes Pathname param value" do
-      cl = subject.build_command_line("true", nil => [Pathname.new("/usr/bin/ruby")])
-      expect(cl).to eq "true /usr/bin/ruby"
-    end
-
-    it "sanitizes Pathname param key" do
-      cl = subject.build_command_line("true", Pathname.new("/usr/bin/ruby") => nil)
-      expect(cl).to eq "true /usr/bin/ruby"
-    end
-
-    it "with params as empty Hash" do
-      cl = subject.build_command_line("true", {})
-      expect(cl).to eq "true"
-    end
-
-    it "with params as nil" do
-      cl = subject.build_command_line("true", nil)
-      expect(cl).to eq "true"
-    end
-
-    it "without params" do
-      cl = subject.build_command_line("true")
-      expect(cl).to eq "true"
-    end
-
-    it "with Pathname command" do
-      cl = subject.build_command_line(Pathname.new("/usr/bin/ruby"))
-      expect(cl).to eq "/usr/bin/ruby"
-    end
-
-    it "with Pathname command and params" do
-      cl = subject.build_command_line(Pathname.new("/usr/bin/ruby"), "-v" => nil)
-      expect(cl).to eq "/usr/bin/ruby -v"
-    end
-  end
 end

programming_language: Ruby
filename: command_line_builder_spec.rb
change_type: ModificationType.ADD
diff: @@ -0,0 +1,88 @@
+require 'spec_helper'
+
+describe AwesomeSpawn::CommandLineBuilder do
+  subject { described_class.new }
+
+  let(:params) do
+    {
+      "--user"     => "bob",
+      "--pass"     => "P@$sw0^& |<>/-+*d%",
+      "--db"       => nil,
+      "--desc="    => "Some Description",
+      :symkey      => nil,
+      :symkey_dash => nil,
+      nil          => ["pkg1", "some pkg"]
+    }
+  end
+
+  let (:modified_params) do
+    params.to_a + [123, 456].collect {|pool| ["--pool", pool]}
+  end
+
+  context "#build" do
+    it "sanitizes crazy params" do
+      cl = subject.build("true", modified_params)
+      expect(cl).to eq "true --user bob --pass P@\\$sw0\\^\\&\\ \\|\\<\\>/-\\+\\*d\\% --db --desc=Some\\ Description --symkey --symkey-dash pkg1 some\\ pkg --pool 123 --pool 456"
+    end
+
+    it "handles Symbol keys" do
+      cl = subject.build("true", :abc => "def")
+      expect(cl).to eq "true --abc def"
+    end
+
+    it "handles Symbol keys with tailing '='" do
+      cl = subject.build("true", :abc= => "def")
+      expect(cl).to eq "true --abc=def"
+    end
+
+    it "handles Symbol keys with underscore" do
+      cl = subject.build("true", :abc_def => "ghi")
+      expect(cl).to eq "true --abc-def ghi"
+    end
+
+    it "handles Symbol keys with underscore and tailing '='" do
+      cl = subject.build("true", :abc_def= => "ghi")
+      expect(cl).to eq "true --abc-def=ghi"
+    end
+
+    it "sanitizes Fixnum array param value" do
+      cl = subject.build("true", nil => [1])
+      expect(cl).to eq "true 1"
+    end
+
+    it "sanitizes Pathname param value" do
+      cl = subject.build("true", nil => [Pathname.new("/usr/bin/ruby")])
+      expect(cl).to eq "true /usr/bin/ruby"
+    end
+
+    it "sanitizes Pathname param key" do
+      cl = subject.build("true", Pathname.new("/usr/bin/ruby") => nil)
+      expect(cl).to eq "true /usr/bin/ruby"
+    end
+
+    it "with params as empty Hash" do
+      cl = subject.build("true", {})
+      expect(cl).to eq "true"
+    end
+
+    it "with params as nil" do
+      cl = subject.build("true", nil)
+      expect(cl).to eq "true"
+    end
+
+    it "without params" do
+      cl = subject.build("true")
+      expect(cl).to eq "true"
+    end
+
+    it "with Pathname command" do
+      cl = subject.build(Pathname.new("/usr/bin/ruby"))
+      expect(cl).to eq "/usr/bin/ruby"
+    end
+
+    it "with Pathname command and params" do
+      cl = subject.build(Pathname.new("/usr/bin/ruby"), "-v" => nil)
+      expect(cl).to eq "/usr/bin/ruby -v"
+    end
+  end
+end

programming_language: Ruby