ESB-2018.1772 - [Appliance] Siemens SCALANCE X Switches, RUGGEDCOM WiMAX, RFID 181-EIP, and SIMATIC RF182C: Execute arbitrary code/commands - Remote/unauthenticated 2018-06-15

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.1772
          Advisory (ICSA-18-165-01) Siemens SCALANCE X Switches,
             RUGGEDCOM WiMAX, RFID 181-EIP, and SIMATIC RF182C
                               15 June 2018

===========================================================================

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

Product:           Siemens SCALANCE X Switches
                   Siemens RUGGEDCOM WiMAX
                   Siemens RFID 181-EIP
                   Siemens SIMATIC RF182C
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-4833  

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-18-165-01

- --------------------------BEGIN INCLUDED TEXT--------------------

Advisory (ICSA-18-165-01)
Siemens SCALANCE X Switches, RUGGEDCOM WiMAX, RFID 181-EIP, and SIMATIC RF182C
Original release date: June 14, 2018

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/.


1. EXECUTIVE SUMMARY

  o CVSS v3 7.5
  o ATTENTION: Exploitable from the same local network segment (OSI Layer 2)
  o Vendor: Siemens
  o Equipment: SCALANCE X switches, RUGGEDCOM WiMAX, RFID 181-EIP, and SIMATIC
    RF182C
  o Vulnerability: Permissions, Privileges, and Access Controls

2. RISK EVALUATION

By sending a specially-crafted DHCP response to a client's DHCP request, an
unprivileged remote attacker could execute arbitrary code.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports the vulnerability affects the following products:

  o RFID 181-EIP: All versions,
  o RUGGEDCOM WiMAX: v4.4 and v4.5,
  o SCALANCE X-200: All versions prior to v5.2.3,
  o SCALANCE X-200 IRT: All versions prior to v5.4.1,
  o SCALANCE X-204RNA: All versions,
  o SCALANCE X-300: All versions,
  o SCALANCE X408: All versions,
  o SCALANCE X414: All versions, and
  o SIMATIC RF182C: All versions.

3.2 VULNERABILITY OVERVIEW

3.2.1    PERMISSIONS, PRIVILEGES, AND ACCESS CONTROLS CWE-264

Unprivileged remote attackers located in the same local network segment (OSI
Layer 2) could gain remote code execution on the affected products by sending a
specially-crafted DHCP response to a client's DHCP request.

CVE-2018-4833 has been assigned to this vulnerability. A CVSS v3 base score of
7.5 has been calculated; the CVSS vector string is
(AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

  o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Energy, Food and Agriculture,
    Healthcare and Public Health, Transportation Systems, and Water and
    Wastewater Systems
  o COUNTRIES/AREAS DEPLOYED: Worldwide
  o COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Dr. Ang Cui and Joseph Pantoga from Red Balloon Security reported this
vulnerability to Siemens Product CERT.

4. MITIGATIONS

Siemens has provided updates for the following products to fix the
vulnerability:

  o SCALANCE X-200: Update to v5.2.3

https://support.industry.siemens.com/cs/cn/en/view/109758142

  o SCALANCE X-200 IRT: Update to v5.4.1

https://support.industry.siemens.com/cs/de/en/view/109758144

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

  o Use static IP addresses instead of DHCP
  o Apply cell protection concept: https://www.siemens.com/cert/
    operational-guidelines-industrial-security
  o Apply Defense-in-Depth: https://www.siemens.com/cert/
    operational-guidelines-industrial-security

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

Additional information on Industrial Security by Siemens can be found at:

https://www.siemens.com/industrialsecurity

For more information on this vulnerability and associated software updates,
please see Siemens security advisory SSA-181018 on their website:

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

NCCIC recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability. Specifically, users should:

  o Minimize network exposure for all control system devices and/or systems,
    and ensure that they are not accessible from the Internet.
  o Locate control system networks and remote devices behind firewalls, and
    isolate them from the business network.
  o 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.

NCCIC reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.

NCCIC 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
on the ICS-CERT website in the Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Strategies.

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

No known public exploits specifically target this vulnerability. High skill
level is needed to exploit.


Contact Information

For any questions related to this report, please contact the NCCIC at:

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  http://
ics-cert.us-cert.gov
or incident reporting:  https://ics-cert.us-cert.gov/Report-Incident?

The NCCIC continuously strives to improve its products and services. You can
help by choosing one of the links below to provide feedback about this product.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        https://www.auscert.org.au/bulletins/

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=Bk5p
-----END PGP SIGNATURE-----