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# SSA-635129: Denial-of-Service Vulnerabilities in EN100 Ethernet Communication Module
and SIPROTEC 5 relays

Publication Date:        2018-07-11
Last Update:             2019-02-12
Current Version:         1.2
CVSS v3.0 Base Score:    7.5

SUMMARY
=======

The EN100 Ethernet communication module and SIPROTEC 5 relays are
affected by security vulnerabilities which could allow an attacker to
conduct a Denial-of-Service attack over the network.

Siemens has released updates for several affected products, is working
on updates for the remaining affected products, and recommends specific
countermeasures until fixes are available.


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


* Firmware variant IEC 61850 for EN100 Ethernet module 
  - Affected versions:
       All versions < V4.33
  - Remediation:
       Update to V4.33
  - Download:
       https://support.industry.siemens.com/cs/us/en/view/109745821
       
       Applying the update causes the module to go through a single restart
       cycle.

* Firmware variant PROFINET IO for EN100 Ethernet module 
  - Affected versions:
       All versions
  - Remediation:
        See recommendations from section Workaround and Mitigations

* Firmware variant Modbus TCP for EN100 Ethernet module 
  - Affected versions:
       All versions
  - Remediation:
        See recommendations from section Workaround and Mitigations

* Firmware variant DNP3 TCP for EN100 Ethernet module 
  - Affected versions:
       All versions
  - Remediation:
        See recommendations from section Workaround and Mitigations

* Firmware variant IEC104 for EN100 Ethernet module 
  - Affected versions:
       All versions < V1.22
  - Remediation:
       Update to V1.22
  - Download:
       https://support.industry.siemens.com/cs/us/en/view/109745821
       
       Applying the update causes the module to go through a single restart
       cycle.

* SIPROTEC 5 relays with CPU variants CP300 and CP100 and the respective
Ethernet communication modules 
  - Affected versions:
       All versions < V7.80
  - Affected by vulnerabilities:
    - CVE-2018-11451
  - Remediation:
       Update to firmware version V7.80 for the following device types: 6MD85,
       6MD86, 7SS85, 7KE85, 7UM85, 7SA87, 7SD87, 7SL87, 7VK87, 7SA82, 7SA86,
       7SD82, 7SD86, 7SL82, 7SL86, 7SJ86, 7SK82, 7SK85, 7SJ82, 7SJ85, 7UT82,
       7UT85, 7UT86, and 7UT87.
  - Download:
       Search for "SIPROTEC 5 <Device type> - DIGSI Device Drivers V7.8x" under
       https://support.industry.siemens.com/.
       
       The firmware version V7.80 for the communications modules can also be
       found on each device specific download page: See under "Additional DIGSI
       Device Driver - V7.8x", article "Protocols".
       
       Applying the update causes the device / module to go through a single
       restart cycle.

* SIPROTEC 5 relays with CPU variants CP200 and the respective Ethernet
communication modules 
  - Affected versions:
       All versions < V7.58
  - Affected by vulnerabilities:
    - CVE-2018-11451
  - Remediation:
       Update to firmware version V7.58 for the following device types: 6MD85,
       6MD86, 7SS85, 7KE85, 7UM85, 7SA87, 7SD87, 7SL87, 7VK87, 7SA82, 7SA86,
       7SD82, 7SD86, 7SL82, 7SL86, 7SJ86, 7SK82, 7SK85, 7SJ82, 7SJ85, 7UT82,
       7UT85, 7UT86, and 7UT87.
  - Download:
       Search for “SIPROTEC 5 <Device type> - DIGSI Device Drivers V7.58” under
       https:/support.industry.siemens.com/. The firmware version V7.58 for the
       device can be found under the section “Previous Versions.”
       
       The firmware version V7.58 for the communications modules can also be
       found on each device’s download page. See in the “Previous Versions”
       section, article “Protocols”.
       
       Applying the update causes the device / module to go through a single
       restart cycle.


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

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

* Block access to port 102/tcp e.g. with an external firewall.
  


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

Siemens strongly recommends applying the provided security updates using
the corresponding tooling and documented procedures made available with
the product. If supported by the product, an automated means to apply
the security updates across multiple product instances may be used.
Siemens strongly recommends prior validation of any security update
before being applied, and supervision by trained staff of the update
process in the target environment.

As a general security measure Siemens strongly recommends to protect
network access with appropriate mechanisms (e.g. firewalls,
segmentation, VPN). It is advised to configure the environment according
to our operational guidelines in order to run the devices in a protected
IT environment.

Recommended security guidelines to Secure Substations can be found at:

https://www.siemens.com/gridsecurity

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

The EN100 Ethernet modules are used for enabling process communication
on either IEC 61850, PROFINET IO, Modbus TCP, DNP3 TCP or IEC 104
protocols via electrical/optical 100 Mbit interfaces on SIPROTEC 4,
SIPROTEC Compact and Reyrolle devices.

SIPROTEC 5 devices provide a wide range of integrated protection,
control, measurement, and automation functions for electrical
substations and other fields of application.



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

The vulnerability classification has been performed by using the CVSS scoring
system in version 3.0 (CVSS v3.0) (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.


* Vulnerability CVE-2018-11451

  Specially crafted packets to port 102/tcp could cause a
  denial-of-service condition in the affected products. A manual restart
  is required to recover the EN100 module functionality of the affected
  devices.
  
  Successful exploitation requires an attacker with network access to send
  multiple packets to the affected products or modules. As a precondition
  the IEC 61850-MMS communication needs to be activated on the affected
  products or modules. No user interaction or privileges are required to
  exploit the vulnerability. The vulnerability could allow causing a
  Denial-of-Service condition of the network functionality of the device,
  compromising the availability of the system.
  
  At the time of advisory publication no public exploitation of this
  security vulnerability was known.

  CVSS v3.0 Base Score: 7.5
  CVSS v3.0 Vector:     CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C

* Vulnerability CVE-2018-11452

  Specially crafted packets to port 102/tcp could cause a
  denial-of-service condition in the EN100 communication module if
  oscillographs are running. A manual restart is required to recover the
  EN100 module functionality.
  
  Successful exploitation requires an attacker with network access to send
  multiple packets to the EN100 module. As a precondition the IEC
  61850-MMS communication needs to be activated on the affected EN100
  modules. No user interaction or privileges are required to exploit the
  security vulnerability. The vulnerability could allow causing a
  Denial-of-Service condition of the network functionality of the device,
  compromising the availability of the system.
  
  At the time of advisory publication no public exploitation of this
  security vulnerability was known.

  CVSS v3.0 Base Score: 5.9
  CVSS v3.0 Vector:     CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C


ACKNOWLEDGMENTS
===============

Siemens thanks the following parties for their efforts:

   * Victor Nikitin, Vladislav Suchkov, and Ilya Karpov from ScadaX for coordinated disclosure



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 (2018-07-11): Publication Date
V1.1 (2018-12-11): Added update information for SIPROTEC 5 relays with CPU variants CP300,
CP200 and CP100 and the respective Ethernet communication modules
V1.2 (2019-02-12): Added update information for firmware variant IEC104 for EN100 Ethernet
modules

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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