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Date: Thu, 4 Jul 2019 09:25:36 +0200
From: Matthias Deeg <>
To: <>
Subject: [FD] [SYSS-2019-021]: WolfVision Cynap - Use of Hard-coded
 Cryptographic Key (CWE-321)

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)



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'


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 ./ --online

WolfVision vSolution Cynap Keygen


          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].



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



[1] Product website for WolfVision Cynap

[2] WolfVision firmware downloads

[3] SySS Security Advisory SYSS-2019-021

[4] SySS Responsible Disclosure Policy

[5] SySS Proof-of-Concept Video "Administrating WolfVision Cynap the
Hacker's Way"



This security vulnerability was found by Manuel Stotz and Gerhard

Klostermeier of SySS GmbH.

E-Mail: manuel.stotz (at)

Public Key:

Key fingerprint = F051 5B74 7E70 193E 7F66 0133 E790 F68A BCE6 8C6D

E-Mail: gerhard.klostermeier (at)

Public Key:

Key fingerprint = 8A9E 75CC D510 4FF6 8DB5 CC30 3802 3AAB 573E B2E7



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




Creative Commons - Attribution (by) - Version 3.0


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