Exploit-DB #41159
Description: PHP PEAR HTTP_Upload 1.0.0b3 - Arbitrary File Upload
Type: webapps
Platform: php
Date: 2017-01-26
Author: hyp3rlinx

Exploit:
[+]################################################################################################
[+] Credits: John Page AKA Hyp3rlinx
[+] Website: hyp3rlinx.altervista.org
[+] Source: http://hyp3rlinx.altervista.org/advisories/PEAR-HTTP_UPLOAD-ARBITRARY-FILE-UPLOAD.txt
[+] ISR: ApparitionSEC
[+]################################################################################################



Vendor:
============
pear.php.net



Product:
====================
HTTP_Upload v1.0.0b3

Download:
https://pear.php.net/manual/en/package.http.http-upload.php

Easy and secure managment of files submitted via HTML Forms.

pear install HTTP_Upload

This class provides an advanced file uploader system for file uploads made
from html forms. Features:
* Can handle from one file to multiple files.
* Safe file copying from tmp dir.
* Easy detecting mechanism of valid upload, missing upload or error.
* Gives extensive information about the uploaded file.
* Rename uploaded files in different ways: as it is, safe or unique
* Validate allowed file extensions
* Multiple languages error messages support (es, en, de, fr, it, nl, pt_BR)


Vulnerability Type:
======================
Arbitrary File Upload



CVE Reference:
==============
N/A



Vulnerability Details:
=====================

The package comes with an "upload_example.php" file to test the package,
when uploading a "restricted" PHP file
user will get message like "Unauthorized file transmission".

Line: 488 of "Upload.php"
var $_extensionsCheck = array('php', 'phtm', 'phtml', 'php3', 'inc');

If user does not go thru the "Upload.php" code line by line. They will find
option to set case sensitive check.
e.g. Line: 503  "$_extensionsCaseSensitive"=true

Line: 874

* @param bool $case_sensitive whether extension check is case sensitive.

* When it is case insensitive, the extension

* is lowercased before compared to the array

* of valid extensions.


This setting looks to prevent mixed or uppercase extension on disallowed
PHP file type bypass before uploading.

However, some developers are unaware that "Apache" can process file with
extension like PHP.1, PHP.; etc.
if the last extension is not specified in the list of mime-types known to
the web server.

Therefore, attackers can easily bypass the security check by appending ".1"
to end of the file,
which can result in arbitrary command execution on the affected server.

e.g.

"ext_bypass.php.1" contents:

<?php

echo passthru('cat /etc/passwd');

?>


Sucessfully Tested on: Bitnami wampstack-5.6.29-0.
Server version: Apache/2.4.23 (Win64)

Sucessfully Tested on: XAMPP for Linux 5.6.8-0
Server version: Apache/2.4.12 (Unix)



Disclosure Timeline:
======================================
Vendor Notification: December 31, 2016
Similar bug reported and open 2012
Issue Fixed: January 17, 2017
January 25, 2017  : Public Disclosure




Severity Level:
================
High




[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no
warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory,
provided that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in
vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the
information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author
prohibits any malicious use of security related information
or exploits by the author or elsewhere.