ESB-2017.1755 - [Android] Siemens SIMATIC Sm@rtClient Android App: Multiple vulnerabilities 2017-07-14

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.1755
     Advisory (ICSA-17-194-03) Siemens SIMATIC Sm@rtClient Android Ap
                               14 July 2017

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Siemens SIMATIC Sm@rtClient Android App
Publisher:         US-CERT
Operating System:  Android
Impact/Access:     Access Privileged Data         -- Remote/Unauthenticated
                   Provide Misleading Information -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-6871 CVE-2017-6870 

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-17-194-03

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Advisory (ICSA-17-194-03)

Siemens SIMATIC Sm@rtClient Android App

Original release date: July 13, 2017

Legal Notice

All information products included in http://ics-cert.us-cert.gov are provided
"as is" for informational purposes only. The Department of Homeland Security 
(DHS) does not provide any warranties of any kind regarding any information 
contained within. DHS does not endorse any commercial product or service, 
referenced in this product or otherwise. Further dissemination of this product
is governed by the Traffic Light Protocol (TLP) marking in the header. For 
more information about TLP, see http://www.us-cert.gov/tlp/.

CVSS v3 7.4

ATTENTION: Remotely exploitable/low skill level to exploit.

Vendor: Siemens

Equipment: SIMATIC Sm@rtClient Android App

Vulnerabilities: Man-in-the-Middle, Authentication Bypass Using an Alternate 
Path or Channel

AFFECTED PRODUCTS

Siemens reports that the vulnerabilities affect the following SIMATIC 
Sm@rtClient Android apps for remote operation and monitoring of SIMATIC HMI 
systems:

SIMATIC WinCC Sm@rtClient for Android: All versions prior to V1.0.2.2

SIMATIC WinCC Sm@rtClient Lite for Android: All versions prior to V1.0.2.2

IMPACT

Successful exploitation of these vulnerabilities could allow an attacker in a
privileged network position to read and modify data within a Transport Layer 
Security TLS session.

MITIGATION

Siemens has released SIMATIC WinCC Sm@rtClient V1.0.2.2 for Android to address
these vulnerabilities and recommends updating as soon as possible. Updates 
will be installed automatically if the mobile device is configured 
accordingly. If the update does not install automatically, users can find the
latest version at the Google Play Store:

https://play.google.com/store/search?q=Sm@rtClient (link is external)

It is advised to configure the environment according to operational 
guidelines.

For more information on these vulnerabilities and more detailed mitigation 
instructions, please see Siemens Security Advisory SSA-589378 at the following
location:

http://www.siemens.com/cert/advisories (link is external)

NCCIC/ICS-CERT recommends that users take defensive measures to minimize the 
risk of exploitation of these vulnerabilities. Specifically, users should:

Minimize network exposure for all control system devices and/or systems, and 
ensure that they are not accessible from the Internet.

Locate control system networks and remote devices behind firewalls, and 
isolate them from the business network.

When remote access is required, use secure methods, such as Virtual Private 
Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be
updated to the most current version available. Also recognize that VPN is only
as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk 
assessment prior to deploying defensive measures.

ICS-CERT also provides a section for control systems security recommended 
practices on the ICS-CERT web page. Several recommended practices are 
available for reading and download, including Improving Industrial Control 
Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly 
available in the ICS-CERT Technical Information Paper, 
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation 
Strategies, that is available for download from the ICS-CERT web site.

Organizations observing any suspected malicious activity should follow their 
established internal procedures and report their findings to ICS-CERT for 
tracking and correlation against other incidents.

In addition, ICS-CERT recommends that users take the following measures to 
protect themselves from social engineering attacks:

Do not click web links or open unsolicited attachments in email messages.

Refer to Recognizing and Avoiding Email Scams for more information on avoiding
email scams.

Refer to Avoiding Social Engineering and Phishing Attacks for more information
on social engineering attacks.

No known public exploits specifically target these vulnerabilities.

VULNERABILITY OVERVIEW

CHANNEL ACCESSIBLE BY NON-ENDPOINT ('MAN-IN-THE-MIDDLE') CWE-300

The existing TLS protocol implementation could allow an attacker to read and 
modify data within a TLS session while performing a man-in-the-middle attack.
This vulnerability affects only SIMATIC WinCC Sm@rtClient for Android.

CVE-2017-6870 has been assigned to this vulnerability. A CVSS v3 base score of
7.4 has been calculated; the CVSS vector string is 
(AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).

AUTHENTICATION BYPASS USING AN ALTERNATE PATH OR CHANNEL CWE-288

An attacker with physical access to an unlocked mobile device that has the 
affected app running could bypass the app's authentication mechanism under 
certain conditions. SIMATIC WinCC Sm@rtClient Lite for Android is only 
affected by this vulnerability.

CVE-2017-6871 has been assigned to this vulnerability. A CVSS v3 base score of
4.6 has been calculated; the CVSS vector string is 
(AV:P/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N).

RESEARCHER

Karsten Sohr and Timo Glander from the TZI at the University of Bremen 
reported these vulnerabilities to Siemens.

BACKGROUND

Critical Infrastructure Sector: Chemical, Energy, Food and Agriculture, and 
Water and Wastewater Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Germany

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: ics-cert@hq.dhs.gov (link sends e-mail)

Toll Free: 1-877-776-7585

International Callers: (208) 526-0900

For industrial control systems security information and incident reporting: 
http://ics-cert.us-cert.gov

ICS-CERT contin

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