VLC Media Player iOS App 2.7.8 File Disclosure

`SEC Consult Vulnerability Lab Security Advisory < 20170913-1 >  
=======================================================================  
title: Local File Disclosure  
product: VLC media player iOS app  
vulnerable version: 2.7.8  
fixed version: 2.8.1  
CVE number: -  
impact: Medium  
homepage: https://itunes.apple.com/us/app/vlc-for-mobile/id650377962?mt=8  
found: 2017-08-22  
by: Ahmad Ramadhan Amizudin (Office Malaysia)  
SEC Consult Vulnerability Lab  
  
An integrated part of SEC Consult  
Bangkok - Berlin - Linz - Montreal - Moscow  
Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich  
  
https://www.sec-consult.com  
  
=======================================================================  
  
Vendor description:  
-------------------  
"VLC is a free and open source cross-platform multimedia player and framework  
that plays most multimedia files as well as DVDs, Audio CDs, VCDs, and various  
streaming protocols."  
  
Source: https://itunes.apple.com/us/app/vlc-for-mobile/id650377962?mt=8  
  
  
Business recommendation:  
------------------------  
The identified vulnerability allows attackers to steal arbitrary files  
(accessible by the app) from the mobile device.  
  
SEC Consult recommends not to enable "Sharing over WiFi" feature in VLC  
for iOS which allows wireless file transfer to/from PC until a thorough  
security review has been performed by security professionals and all  
identified issues have been resolved.  
  
  
Vulnerability overview/description:  
-----------------------------------  
1) Local file disclosure  
The 'Sharing over WiFi' feature in VLC for iOS is vulnerable to a local file  
disclosure vulnerability. An attacker can read any files which can be accessed  
with current application privileges. This issue can lead to data theft.  
  
  
Proof of concept:  
-----------------  
1) Local file disclosure  
The example below shows how the LFD vulnerability can be exploited.  
  
URL : http://$IP:$PORT/download/<path-to-file-or-folder>  
METHOD : GET  
EXAMPLE : http://$IP:$PORT/download//etc/passwd  
  
  
The source code excerpt below shows the vulnerable code of the mobile app:  
  
VULN. FILE : Sources/VLCHTTPConnection.m  
VULN. CODE :  
[...]  
- (NSObject<HTTPResponse> *)_httpGETDownloadForPath:(NSString *)path  
{  
NSString *filePath = [[path stringByReplacingOccurrencesOfString:@"/download/"  
withString:@""]stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  
HTTPFileResponse *fileResponse = [[HTTPFileResponse alloc]  
initWithFilePath:filePath forConnection:self];  
fileResponse.contentType = @"application/octet-stream";  
return fileResponse;  
}  
[...]  
  
  
Vulnerable / tested versions:  
-----------------------------  
VLC version 2.7.8 has been tested on iOS 10.3.3 and found to be vulnerable.  
  
  
Vendor contact timeline:  
------------------------  
2017-08-23: Contacting vendor through email  
2017-08-23: Vendor replied, they are looking at it  
2017-09-05: Asked for a status update from the vendor  
2017-09-09: Vendor released patch in version 2.8.1  
2017-09-13: Public release of advisory  
  
  
Solution:  
---------  
Upgrade to the latest version available:  
https://itunes.apple.com/us/app/vlc-for-mobile/id650377962?mt=8  
  
  
Workaround:  
-----------  
Disable the 'Sharing over WiFi' feature.  
  
  
Advisory URL:  
-------------  
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html  
  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
SEC Consult Vulnerability Lab  
  
SEC Consult  
Bangkok - Berlin - Linz - Luxembourg - Montreal - Moscow  
Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich  
  
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of new offensive and defensive technologies for our customers. Hence our  
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recommendation about the risk profile of new technologies.  
  
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EOF Ahmad Ramadhan / @2017  
  
`