Dropbox 6.4.14 DLL Hijacking Vulnerability

[mehta.himanshu21@xxxxxxxxx]

Aloha,

Summary
Dropbox Installer for Windows contains a DLL hijacking vulnerability that could 
allow an unauthenticated, remote attacker to execute arbitrary code on the 
targeted system. The vulnerability exists due to some DLL file is loaded by 
'DropboxInstaller.exe' improperly. And it allows an attacker to load this DLL 
file of the attacker?s choosing that could execute arbitrary code without the 
user's knowledge.

Affected Product: Dropbox 6.4.14 and prior versions

Tested on: Windows 7

Impact
Attacker can exploit this vulnerability to load a DLL file of the attacker's 
choosing that could execute arbitrary code. This may help attacker to 
Successful exploit the system if user creates shell as a DLL.

Vulnerability Scoring Details
The vulnerability classification has been performed by using the CVSSv2 scoring 
system (http://www.first.org/cvss/).
Base Score: 7.2 (AV:L/AC:L/Au:N/C:C/I:C/A:C)

More Details:
For software downloaded with a web browser the application directory is 
typically the user's "Downloads" directory: see 
https://insights.sei.cmu.edu/cert/2008/09/carpet-bombing-and-directory-poisoning.html,
http://blog.acrossecurity.com/2012/02/downloads-folder-binary-planting.html
and http://seclists.org/fulldisclosure/2012/Aug/134 for "prior art" about this 
well-known and well-documented vulnerability.

If an attacker places malicious DLL in the user's "Downloads" directory (for 
example per "drive-by download" or "social engineering") this vulnerability 
becomes a remote code execution.

Proof of concept/demonstration:

1. Create a malicious PGPmapih.dll file and save it in your "Downloads" 
directory. 

2. Download 'DropboxInstaller.exe' from https://www.dropbox.com/downloading and 
save it in your "Downloads" directory. 

3. Execute .exe from your "Downloads" directory. 

4. Malicious dll file gets executed. 

Informed Vendor: Yes
Fixed Version: TBA

Please assign a CVE ID.

Chao!! 
Himanshu Mehta