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Hash: SHA512  
  
Advisory ID: SYSS-2019-021  
Product: Cynap  
Manufacturer: WolfVision  
Affected Version(s): 1.18g, 1.28j  
Tested Version(s): 1.18g, 1.28j  
Vulnerability Type: Use of Hard-coded Cryptographic Key (CWE-321)  
Risk Level: High  
Solution Status: Fixed  
Manufacturer Notification: 2019-05-03  
Solution Date: 2019-06-19  
Public Disclosure: 2019-07-04  
CVE Reference: Not assigned yet  
Authors of Advisory: Manuel Stotz, Gerhard Klostermeier (SySS GmbH)  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Overview:  
  
WolfVision Cynap is a wireless collaboration and presentation system.  
  
The manufacturer describes the product as follows [1]:  
  
"Cynap is a stand-alone all-in-one wireless collaboration and  
presentation system which includes a built-in media player, web  
conferencing, on-board recording and streaming , BYOD screen sharing  
for all mobile devices, and annotation functionality, making it the  
ideal device to form the centrepiece of new and adapted classrooms and  
meeting spaces."  
  
Due to the use of a hard-coded cryptographic key, an attacker can   
generate support PINs for resetting the administrative user password in  
order to gain administrative access to the device.  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Vulnerability Details:  
  
SySS GmbH found out that the WolfVision Cynap wireless collaboration  
and presentation system uses a static, hard-coded cryptographic secret  
for generating support PINs used for the provided 'forgot password'  
functionality.  
  
By knowing this static secret and the corresponding algorithm for  
calculating support PINs, an attacker can reset the password of the  
administrative user account "ADMIN" and thus gain unauthorized access to  
the affected Cynap device via a network connection.  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Proof of Concept (PoC):  
  
SySS GmbH developed a software tool for generating support PINs either  
in online or offline mode.  
  
The following output of the software tools illustrates a successful  
attack resulting in a reset password for the administrative user  
account "ADMIN".  
  
$ python ./wolfvision_cynap_keygen.py --online 192.168.40.109  
WolfVision vSolution Cynap Keygen  
by   
Manuel Stotz   
Gerhard Klostermeier   
  
[*] Launch keygen in online mode ... [OK]  
[*] Gathering data ... [OK]  
[*] Serialnumber: <SERIAL NUMBER>  
[*] Support PIN: 447301  
[*] Generating new Support PIN ... [OK]  
[+] New Support PIN: 723247  
[*] Account: ADMIN  
[*] Password: Password  
[*] Bye!  
  
A successful attack against a vulnerable WolfVision Cynap device gaining  
administrative access is demonstrated in our SySS PoC video  
"Administrating WolfVision Cynap the Hacker's Way" [5].  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Solution:  
  
Install the firmware version 1.30j provided by the manufacturer  
WolfVision [2].  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Disclosure Timeline:  
  
2019-05-03: Vulnerability reported to manufacturer  
2019-05-10: Vulnerability reported to manufacturer again  
2019-05-13: Manufacturer confirms receipt of security advisory  
2019-05-31: Manufacturer schedules firmware update 1.30j with fix for  
the reported security issue  
2019-06-19: Release of firmware update 1.30j including security fix  
2019-07-04: Public release of SySS security advisory  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
References:  
  
[1] Product website for WolfVision Cynap   
https://www.wolfvision.com/vsolution/index.php/en/presentation-systems/cynap/cynap  
[2] WolfVision firmware downloads  
https://wolfvision.com/vsolution/index.php/de/support/downloads  
[3] SySS Security Advisory SYSS-2019-021  
https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2019-021.txt  
[4] SySS Responsible Disclosure Policy  
https://www.syss.de/en/responsible-disclosure-policy/  
[5] SySS Proof-of-Concept Video "Administrating WolfVision Cynap the Hacker's Way"  
https://youtu.be/veEtiYAWvMY  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Credits:  
  
This security vulnerability was found by Manuel Stotz and Gerhard  
Klostermeier of SySS GmbH.  
  
E-Mail: manuel.stotz (at) syss.de  
Public Key: https://www.syss.de/fileadmin/dokumente/PGPKeys/Manuel_Stotz.asc  
Key fingerprint = F051 5B74 7E70 193E 7F66 0133 E790 F68A BCE6 8C6D  
  
E-Mail: gerhard.klostermeier (at) syss.de  
Public Key: https://www.syss.de/fileadmin/dokumente/PGPKeys/Gerhard_Klostermeier.asc  
Key fingerprint = 8A9E 75CC D510 4FF6 8DB5 CC30 3802 3AAB 573E B2E7  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Disclaimer:  
  
The information provided in this security advisory is provided "as is"   
and without warranty of any kind. Details of this security advisory may   
be updated in order to provide as accurate information as possible. The  
latest version of this security advisory is available on the SySS Web   
site.  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
Copyright:  
  
Creative Commons - Attribution (by) - Version 3.0  
URL: http://creativecommons.org/licenses/by/3.0/deed.en  
  
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