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Advisory:          2004-Nuke-001
Affected Software: PHPNuke
Affected Versions: Version 7.3 and earlier
Main Developer:    Francisco Burzi  (http://www.phpnuke.org/)
Module Developers: See credits section below



Description:  
-----------

PhpNuke is a very popular open source portal software for building dynamic 
websites.  It is a fork of Thatware and has been under active development 
since mid-2000.  Over the years, PhpNuke itself has spawned a number of 
software forks.



Vulnerability: 
------------- 

In an effort to secure files from being directly accessed by outside visitors,
PhpNuke's core, module, and patch developers added a simple security checking 
mechanism.  If the checker evaluates to false, the remaining code inside the 
file is executed.  If it evaluates to true, the script aborts or the visitor 
is redirected to another page.

The process consists of capturing the currently executing script's path and 
filename with the global variable $_SERVER['PHP_SELF'].  Using PHP's built-in 
function eregi(), this value is then compared against the script's name 
which should be the sole access point.

Example:
if (!eregi("admin.php", $_SERVER['PHP_SELF'])) { die ("Access Denied"); }

In this example, a file with the above snippet will continue executing if 
it was accessed by another file containing the letters "admin.php" (without 
quotes) otherwise the script aborts returning the words "Access Denied".  

Using eregi() with the NOT logical operator as done by PhpNuke's developers 
is a very poor way to control file access because anyone can easily 
manipulate a URL and add the missing component thereby forcing the security 
check to always evaluate to false and gain unfettered entry.



Exploitation Example:
---------------------

http://www.domain.com/admin/case/case.adminfaq.php/admin.php?op=FaqCatGo



Impact:
------

In the majority of cases here, exploition of this vulnerability will display 
full path disclosure and not continue further code execution where intrusion 
or damage might occur.  In a much smaller number of cases, the code may 
continue executing and possibly allow outsiders unwanted access to some 
restricted areas on the site.  Those who have setup their servers to look in 
the main directory when a file is not located in the current one may see   
a higher percentage of unwanted access and a lower percentage of full path 
disclosures than others.

PhpNuke's code was not analyzed on whether additional vulnerabilities are 
possible due to this security weakness.  However, files where potential SQL 
injections might occur are flagged below.



Affected Files:
--------------

Although an effort was made to identify all affected files, we leave it 
up to the developers/users to do their own verification to ensure no files 
were inadvertently missed.

There are ~138 files affected.  Of these, ~27 have no security check in 
PhpNuke's original distribution.  A software patch was released by chatserv 
from NukeFixes  (http://www.nukefixes.com) and NukeResources 
(http://www.nukeresources.com) to correct a number of vulnerability issues.  
Although 25 of the 27 files had a security check added, chatserv used the 
same inadequate method described in this report.

Note 1 --> /admin/case/case.adminfaq.php
Note 1 --> /admin/case/case.authors.php
Note 1 --> /admin/case/case.backup.php
Note 1 --> /admin/case/case.banners.php
Note 1 --> /admin/case/case.blocks.php
Note 1 --> /admin/case/case.comments.php
Note 1 --> /admin/case/case.content.php
Note 1 --> /admin/case/case.download.php
Note 1 --> /admin/case/case.encyclopedia.php
Note 1 --> /admin/case/case.ephemerids.php
Note 1 --> /admin/case/case.forums.php
Note 1 --> /admin/case/case.groups.php
Note 1 --> /admin/case/case.links.php
Note 1 --> /admin/case/case.messages.php
Note 1 --> /admin/case/case.modules.php
Note 1 --> /admin/case/case.newsletter.php
Note 1 --> /admin/case/case.optimize.php
Note 1 --> /admin/case/case.polls.php
Note 1 --> /admin/case/case.referers.php
Note 1 --> /admin/case/case.reviews.php
Note 1 --> /admin/case/case.sections.php
Note 1 --> /admin/case/case.settings.php
Note 1 --> /admin/case/case.stories.php
Note 1 --> /admin/case/case.topics.php
Note 1 --> /admin/case/case.users.php
Note 2 --> /admin/links/links.addstory.php
Note 2 --> /admin/links/links.backup.php
Note 2 --> /admin/links/links.banners.php
Note 2 --> /admin/links/links.blocks.php
Note 2 --> /admin/links/links.content.php
Note 2 --> /admin/links/links.download.php
Note 2 --> /admin/links/links.editadmins.php
Note 2 --> /admin/links/links.editusers.php
Note 2 --> /admin/links/links.encyclopedia.php
Note 2 --> /admin/links/links.ephemerids.php
Note 2 --> /admin/links/links.faq.php
Note 2 --> /admin/links/links.forums.php
Note 2 --> /admin/links/links.groups.php
Note 2 --> /admin/links/links.httpreferers.php
Note 2 --> /admin/links/links.messages.php
Note 2 --> /admin/links/links.modules.php
Note 2 --> /admin/links/links.newsletter.php
Note 2 --> /admin/links/links.optimize.php
Note 2 --> /admin/links/links.reviews.php
Note 2 --> /admin/links/links.sections.php
Note 2 --> /admin/links/links.settings.php
Note 2 --> /admin/links/links.submissions.php
Note 2 --> /admin/links/links.surveys.php
Note 2 --> /admin/links/links.topics.php
Note 2 --> /admin/links/links.weblinks.php
Note 3 --> /admin/modules/adminfaq.php
Note 3 --> /admin/modules/authors.php
Note 3 --> /admin/modules/backup.php
Note 3 --> /admin/modules/banners.php
Note 3 --> /admin/modules/blocks.php
Note 3 --> /admin/modules/comments.php
Note 3 --> /admin/modules/content.php
Note 3 --> /admin/modules/download.php
Note 3 --> /admin/modules/encyclopedia.php
Note 3 --> /admin/modules/ephemerids.php
Note 3 --> /admin/modules/forums.php
Note 3 --> /admin/modules/groups.php
Note 3 --> /admin/modules/links.php
Note 3 --> /admin/modules/messages.php
Note 3 --> /admin/modules/modules.php
Note 3 --> /admin/modules/newsletter.php
Note 3 --> /admin/modules/optimize.php
Note 3 --> /admin/modules/polls.php
Note 3 --> /admin/modules/referers.php
Note 3 --> /admin/modules/reviews.php
Note 3 --> /admin/modules/sections.php
Note 3 --> /admin/modules/settings.php
Note 3 --> /admin/modules/stories.php
Note 3 --> /admin/modules/topics.php
Note 3 --> /admin/modules/users.php
Note 4 --> /db/db.php
Note 1 --> /modules/AvantGo/index.php
Note 1 --> /modules/AvantGo/print.php
Note 1 --> /modules/Content/index.php
Note 1 --> /modules/Downloads/index.php
Note 5 --> /modules/Downloads/voteinclude.php
Note 1 --> /modules/Encyclopedia/index.php
Note 1 --> /modules/Encyclopedia/search.php
Note 1 --> /modules/FAQ/index.php
Note 1 --> /modules/Feedback/index.php
Note 1 --> /modules/Forums/faq.php
Note 1 --> /modules/Forums/groupcp.php
Note 1 --> /modules/Forums/index.php
Note 1 --> /modules/Forums/login.php
Note 1 --> /modules/Forums/modcp.php
Note 1 --> /modules/Forums/nukebb.php
Note 1 --> /modules/Forums/posting.php
Note 1 --> /modules/Forums/profile.php
Note 1 --> /modules/Forums/search.php
Note 1 --> /modules/Forums/update_to_205.php
Note 1 --> /modules/Forums/update_to_206.php
Note 1 --> /modules/Forums/update_to_207.php
Note 1 --> /modules/Forums/viewforum.php
Note 1 --> /modules/Forums/viewonline.php
Note 1 --> /modules/Forums/viewtopic.php
Note 1 --> /modules/Journal/add.php
Note 1 --> /modules/Journal/comment.php
Note 1 --> /modules/Journal/commentkill.php
Note 1 --> /modules/Journal/commentsave.php
Note 1 --> /modules/Journal/delete.php
Note 1 --> /modules/Journal/deleteyes.php
Note 1 --> /modules/Journal/display.php
Note 1 --> /modules/Journal/edit.php
Note 1 --> /modules/Journal/friend.php
Note 1 --> /modules/Journal/functions.php
Note 1 --> /modules/Journal/index.php
Note 1 --> /modules/Journal/modify.php
Note 1 --> /modules/Journal/savenew.php
Note 1 --> /modules/Journal/search.php
Note 1 --> /modules/Members_List/index.php
Note 1 --> /modules/News/article.php
Note 1 --> /modules/News/associates.php
Note 1 --> /modules/News/categories.php
Note 1 --> /modules/News/comments.php
Note 1 --> /modules/News/friend.php
Note 1 --> /modules/News/index.php
Note 1 --> /modules/News/print.php
Note 3 --> /modules/Private_Messages/index.php
Note 1 --> /modules/Recommend_Us/index.php
Note 1 --> /modules/Reviews/index.php
Note 1 --> /modules/Search/index.php
Note 1 --> /modules/Sections/index.php
Note 1 --> /modules/Statistics/index.php
Note 1 --> /modules/Stories_Archive/index.php
Note 1 --> /modules/Submit_News/index.php
Note 1 --> /modules/Surveys/comments.php
Note 1 --> /modules/Surveys/index.php
Note 1 --> /modules/Top/index.php
Note 1 --> /modules/Topics/index.php
Note 1 --> /modules/Web_Links/index.php
Note 5 --> /modules/Web_Links/voteinclude.php
Note 1 --> /modules/Your_Account/index.php
Note 1 --> /modules/Your_Account/navbar.php

**  Some of PhpNuke's earlier versions contain the WebMail module which 
is also affected by this security weakness.


Note 1: Vulnerabilty: Full path disclosure for servers not setup to check
        the main directory when a file is not located in the current 
        directory otherwise the rest of the code is executed.
Note 2: Vulnerability: Full path disclosure.  File has no security check. 
Note 3: Vulnerability: Full path disclosure.  Possibility of SQL injection
        IF the database abstraction layer can be executed while accessing
        this file.
Note 4: Vulnerabilty: Full path disclosure or the code can be made to execute 
        passing in proper variable values. File has no security check.  
Note 5: Vulnerabilty: Full path disclosure for servers not setup to check the
        main directory when a file is not located in the current directory 
        otherwise the rest of the code is executed. File has no security check.



Credits -- Module Developers:
----------------------------

Admin FAQ/Authors/AvantGo/Backup/Banners/Blocks/Comments/Content/
Download/Encyclopedia/Ephemerids/Groups/Links/Messages/Modules/
News/Newsletter/Polls/Recommend Us/Referers/Reviews/Search/Sections/
Settings/Statistics/Stories/Stories Archive/Submit News/Surveys/Top/
Topics/Users/Web Links:
- Francisco Burzi (http://www.phpnuke.org)
- chatserv (http://www.nukefixes.com) (http://www.nukeresources.com)

Admin FAQ:
- Richard Tirtadji AKA King Richard (http://www.nukeaddon.com)
- Hutdik Hermawan AKA hotFix (http://www.nukeaddon.com)

AvantGo:
-  Tim Litwiller (http://linux.made-to-order.net)

Backup:
- Thomas Rudant (http://www.grunk.net) (http://www.securite-internet.org)

Comments:
- Oleg [Dark Pastor] Martos (http://www.rolemancer.ru)

Forums/Members List/Private Messages (PHPBB2 forums code ported to PHPNuke):
- The phpBB Group (http://www.phpbb.com) 
- Tom Nitzschner (http://bbtonuke.sourceforge.net) (http://www.toms-home.com) 
- Paul Laudanski and his team from Computer Cops (http://www.computercops.biz) 
  and NukeCops (http://www.nukecops.com/) "Official" PhpNuke Developers
- chatserv (http://www.nukefixes.com) (http://www.nukeresources.com)  

Journal:
- Joseph Howard (Member's Journal)
- Trevor Scott (Atomic Journal)
- Paul Laudanski and his team from Computer Cops (http://www.computercops.biz) 
  and NukeCops (http://www.nukecops.com/) "Official" PhpNuke Developers

Links:
- James Knickelbein (http://www.journeymilwaukee.com)

Optimize:
- Xavier JULIE (http://www.securite-internet.org) 
- chatserv (http://www.nukefixes.com) (http://www.nukeresources.com) 

Reviews:
- Jeff Lambert (http://www.qchc.com)

Statistics:
- Harry Mangindaan (http://www.nuketest.com)
- Sudirman (http://www.nuketest.com)

Web Links:
- James Knickelbein (http://www.journeymilwaukee.com)

Your Account:
- Francisco Burzi (http://www.phpnuke.org)


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