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# SSA-344983: Vulnerability in WPA2 Key Handling affecting SCALANCE W700 and SCALANCE
W1700 Devices

Publication Date:        2019-12-10
Last Update:             2019-12-10
Current Version:         1.0
CVSS v3.1 Base Score:    6.5

SUMMARY
=======

The latest firmware updates for the SCALANCE W700 and W1700 wireless
device families fix a vulnerability affecting WPA/WPA2 key handling. It
might be possible to, by manipulating the EAPOL-Key frames, decrypt the
Key Data field without the frame being authenticated.

This has impact on WPA/WPA2 architectures using TKIP encryption. The
attacker must be in the wireless range of the device to perform the
attack.


AFFECTED PRODUCTS AND SOLUTION
==============================


* SCALANCE W1700 
  - Affected versions:
       All versions < V1.1
  - Remediation:
       Update to V1.1 or any later version
  - Download:
       https://support.industry.siemens.com/cs/ww/en/view/109762253

* SCALANCE W700 
  - Affected versions:
       All versions < V6.4
  - Remediation:
       Update to V6.4 or any later version
  - Download:
       https://support.industry.siemens.com/cs/ww/en/view/109773308


WORKAROUNDS AND MITIGATIONS
===========================

Siemens has identified the following specific workarounds and mitigations that
customers can apply to reduce the risk:

* Whenever possible, use AES-CCMP instead of TKIP in the WPA/WPA2
networks. This can be configured for both SCALANCE W-700 and W-1700
families over the Web Based Management (web server). For more
information, go for the respective Manual.
  


GENERAL SECURITY RECOMMENDATIONS
================================

As a general security measure, Siemens strongly recommends to protect
network access to devices with appropriate mechanisms. In order to
operate the devices in a protected IT environment, Siemens recommends to
configure the environment according to Siemens' operational guidelines
for Industrial Security (Download:
https://www.siemens.com/cert/operational-guidelines-industrial-security),
and to follow the recommendations in the product manuals.

Additional information on Industrial Security by Siemens can be found
at: https://www.siemens.com/industrialsecurity

PRODUCT DESCRIPTION
===================

SCALANCE W700 products are wireless communication devices used to
connect industrial components like Programmable Logic Controllers (PLCs)
or Human Machine Interfaces (HMIs).

SCALANCE W1700 products are wireless communication devices used to
connect industrial components, like Programmable Logic Controllers
(PLCs) or Human Machine Interfaces (HMIs), according to the IEEE
802.11ac standard.

VULNERABILITY CLASSIFICATION
============================

The vulnerability classification has been performed by using the CVSS scoring
system in version 3.1 (CVSS v3.1) (https://www.first.org/cvss/). The CVSS 
environmental score is specific to the customer's environment and will impact
the overall CVSS score. The environmental score should therefore be 
individually defined by the customer to accomplish final scoring.

An additional classification has been performed using the CWE classification, a
community-developed list of common software security weaknesses. This serves as
a common language and as a baseline for weakness identification, mitigation,
and prevention efforts. A detailed list of CWE classes can be found at:
https://cwe.mitre.org/.



* Vulnerability CVE-2018-14526

  It was discovered that under certain conditions the integrity of
  EAPOL-key messages might not be checked, leading to a decryption oracle.
  
  The security vulnerability could be exploited by an attacker within
  range of the Access Point which could allow the abuse of the
  vulnerability to access confidential data. For this, the Access Point
  must use TKIP as encryption method.
  
  At the time of advisory publication no public exploitation of this
  security vulnerability was known.

  CVSS v3.1 Base Score: 6.5
  CVSS Vector:          CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
  CWE:                  CWE-924: Improper Enforcement of Message Integrity During Transmission in a
Communication Channel




ADDITIONAL INFORMATION
======================

For further inquiries on security vulnerabilities in Siemens products and 
solutions, please contact the Siemens ProductCERT:

https://www.siemens.com/cert/advisories


HISTORY DATA
============

V1.0 (2019-12-10): Publication Date

TERMS OF USE
============

Siemens Security Advisories are subject to the terms and conditions contained
in Siemens' underlying license terms or other applicable agreements previously
agreed to with Siemens (hereinafter "License Terms"). To the extent applicable
to information, software or documentation made available in or through a
Siemens Security Advisory, the Terms of Use of Siemens' Global Website
(https://www.siemens.com/terms_of_use, hereinafter "Terms of Use"), in
particular Sections 8-10 of the Terms of Use, shall apply additionally. In case
of conflicts, the License Terms shall prevail over the Terms of Use.
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