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AUSCERT External Security Bulletin Redistribution
ESB-2015.2310
Siemens RUGGEDCOM ROS IP Forwarding Vulnerability
3 September 2015
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AusCERT Security Bulletin Summary
---------------------------------
Product: Siemens RUGGEDCOM ROS
Publisher: US-CERT
Operating System: Network Appliance
Impact/Access: Unauthorised Access -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2015-6675
Original Bulletin:
https://ics-cert.us-cert.gov/advisories/ICSA-15-244-01
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Advisory (ICSA-15-244-01)
Siemens RUGGEDCOM ROS IP Forwarding Vulnerability
Original release date: September 01, 2015
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
Stephen Craven of the Tennessee Valley Authority (TVA) has identified an IP
forwarding vulnerability in older versions of Siemens RUGGEDCOM ROS. Siemens
recommends updating to the latest version to mitigate this vulnerability.
This vulnerability could be exploited remotely.
AFFECTED PRODUCTS
Siemens reports that the vulnerability affects the following versions of
RUGGEDCOM ROS:
ROS: All versions between 3.8.0 and 4.2.0
ROS on the following products is not affected:
RMC products,
RP110, and
RS950G.
IMPACT
An attacker in one VLAN could possibly circumvent VLAN isolation and
communicate with devices in another VLAN if IP addresses are configured on
both VLANs.
Impact to individual organizations depends on many factors that are unique to
each organization. NCCIC/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.
The affected products, Siemens RUGGEDCOM ROS-based devices, are used to
connect devices that operate in harsh environments such as electric utility
substations and traffic control cabinets. According to Siemens, RUGGEDCOM
ROS-based devices are deployed across several sectors including Energy,
Healthcare and Public Health, and Transportation Systems. Siemens estimates
that these products are used worldwide.
VULNERABILITY CHARACTERIZATION
VULNERABILITY OVERVIEW
UNINTENDED PROXY OR INTERMEDIARY [a]
The ROS operating system for layer 2 switches include IP forwarding
capabilities that cannot be deactivated by users. This may allow an attacker
in one VLAN to possibly circumvent VLAN isolation and communicate with devices
in another VLAN if IP addresses are configured on both VLANs.
CVE-2015-6675 [b] has been assigned to this vulnerability. A CVSS v2 base score
of 4.3 has been assigned; the CVSS vector string is
(AV:A/AC:M/Au:N/C:P/I:P/A:N). [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 medium skill would be able to exploit this vulnerability.
MITIGATION
Firmware versions since ROS 4.2.0 provide an option to disable IP forwarding.
Siemens recommends that users update to the latest firmware version. The
firmware updates for the affected products can be obtained for free from the
following contact points:
Submit a support request online
http://www.siemens.com/automation/support-request
Call a local hotline center:
http://www.automation.siemens.com/mcms/aspa-db/en/automationtechnology/Pages/default.aspx
If users do not want IP forwarding between VLANs in their configuration, then
they need to disable IP forwarding after updating to the new firmware
according to the instructions in the user guide. The following link leads to
the ROS user guide:
https://support.industry.siemens.com/cs/ww/en/ps/15305/man
Until the firmware can be updated to the latest version, users can remove IP
addresses from the VLAN if they are not required.
For more information on this vulnerability and detailed instructions, please
see Siemens Security Advisory SSA-720081 at the following location:
http://www.siemens.com/cert/advisories/
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 at:
http://ics-cert.us-cert.gov/content/recommended-practices. 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 ICSCERT 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
(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.
a. CWE-441: Unintended Proxy or Intermediary ('Confused Deputy'),
http://cwe.mitre.org/data/definitions/441.html, web site last accessed
September 1, 2015.
b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-6675, NIST
uses this advisory to create the CVE web site report. This web site will be
active sometime after publication of this advisory.
c. CVSS Calculator,
http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:A/AC:M/Au:N/C:P/I:P/A:N, web
site last accessed September 1, 2015.
Contact Information
For any questions related to this report, please contact ICS-CERT at:
Email: ics-cert@hq.dhs.gov
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 continuously strives to improve its products and services. You can
help by choosing one of the links below to provide feedback about this
product.
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