U.S. Flag Official website of the Department of Homeland Security
U.S. Department of Homeland Security Seal. ICS-CERT. Industrial Control Systems Cyber Emergency Response Team.
TLP:WHITE

Advisory (ICSA-13-274-01)

Siemens SCALANCE X-200 Authentication Bypass Vulnerability

Original release date: October 03, 2013

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/.



OVERVIEW

This advisory was originally posted to the US-CERT secure Portal library on October 01, 2013, and is now being released to the ICS-CERT-Web page.

Siemens has identified an authentication bypass vulnerability in the SCALANCE X-200 switch product family. Researcher Eireann Leverett of IOActive coordinated disclosure of the vulnerability with Siemens. This issue only applies to switches using older firmware versions and has been fixed from firmware V4.5.0 (non-IRT) and V5.1.0 (IRT) on. Siemens has reported the resolution to ICS-CERT.

This vulnerability could be exploited remotely.

AFFECTED PRODUCTS

Siemens reports that the vulnerability affects the following versions:

  • SCALANCE X-200 switch family with firmware version prior to V4.5.0.
  • SCALANCE X-200IRT (Isochronous Real-Time) switch family with firmware version prior to V5.1.0.

Alternatively, the affected products may be identified by using their Machine-Readable Product Designation (MLFB). Products with the following MLFBs may be affected:

  • SCALANCE X-200 MLFBs:

6GK5224-0BA00-2AA3      6GK5216-0BA00-2AA3      6GK5212-2BB00-2AA3

6GK5212-2BC00-2AA3      6GK5208-0BA10-2AA3      6GK5206-1BB10-2AA3

6GK5206-1BC10-2AA3      6GK5204-2BB10-2AA3      6GK5204-2BC10-2AA3

6GK5208-0HA10-2AA6      6GK5204-0BA00-2AF2      6GK5208-0BA00-2AF2

6GK5206-1BC00-2AF2      6GK5204-2BC00-2AF2      6GK5204-2BB10-2CA2

  • SCALANCE X-200IRT MLFBs:

6GK5201-3JR00-2BA6       6GK5204-0BA00-2BF2      6GK5204-0JA00-2BA6

6GK5202-2JR00-2BA6       6GK5202-2BH00-2BA3      6GK5201-3BH00-2BA3

6GK5200-4AH00-2BA3      6GK5202-2BB00-2BA3      6GK5204-0BA00-2BA3

IMPACT

Successful exploitation of this vulnerability may allow attackers to perform administrative operations over the network without authentication.

Impact to individual organizations depends on many factors that are unique to each organization. ICS‑CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.

BACKGROUND

Siemens is an international company headquartered in Munich, Germany. Siemens develops products mainly in the energy, transportation, and healthcare sectors.

The affected products, SCALANCE X-200 switches, are used to connect industrial components such as PLCs or HMIs. These switches use a Web-based interface that enables administrators to change device configuration using an Internet browser.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

AUTHENTICATION BYPASS ISSUESa

The integrated Web server of SCALANCE X-200 switches might allow attackers to perform administrative operations over the network without authentication.

CVE-2013-5944b has been assigned to this vulnerability. A CVSS v2 base score of 10.0 has been assigned; the CVSS vector string is (AV:N/AC:L/Au:N/C:C/I:C/A:C).c

VULNERABILITY DETAILS

EXPLOITABILITY

This vulnerability could be exploited remotely.

EXISTENCE OF EXPLOIT

No known public exploits specifically target this vulnerability.

DIFFICULTY

An attacker with a low skill would be able to exploit this vulnerability.

MITIGATION

Siemens recommends upgrading to the current SCALANCE X-200 firmware versions V5.0.1 (non-IRT) and V5.1.2 (IRT). These versions are not vulnerable to the authentication bypass issue.

The firmware update for SCALANCE X-200 can be obtained here:

http://support.automation.siemens.com/WW/view/en/78458674

The firmware update for SCALANCE X-200IRT can be obtained here:

http://support.automation.siemens.com/WW/view/en/78454417

Siemens security advisory is located here:

http://www.siemens.com/innovation/pool/de/forschungsfelder/siemens_security_advisory_ssa-176087.pdf

ICS‑CERT encourages asset owners to take additional defensive measures to protect against this and other cybersecurity risks.

  • Minimize network exposure for all control system devices. Critical devices should not directly face 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 VPN is only as secure as the connected devices.

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.d ICS‑CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.

Additional mitigation guidance and recommended practices are publicly available in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B—Targeted Cyber Intrusion Mitigation Strategies,e that is available for download from the ICS-CERT Web page (http://ics-cert.us-cert.gov/).

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.


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.

Was this document helpful?  Yes  |  Somewhat  |  No

Back to Top