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ZMCIRT Vulnerability Bulletin
ZMC-2021.10.15.0800
Siemens RUGGEDCOM ROX Devices: Denial of service - Remote/unauthenticated
15th October 2021
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Product: Siemens RUGGEDCOM ROX Devices
Publisher: ICS-CERT
Operating System: Network Appliance
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2021-41546
Original Bulletin:
https://us-cert.cisa.gov/ics/advisories/icsa-21-287-08
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ICS Advisory (ICSA-21-287-08)
Siemens RUGGEDCOM ROX Devices
Original release date: October 14, 2021
Legal Notice
All information products included in https://us-cert.cisa.gov/ics 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 https://us-cert.cisa.gov/tlp/ .
1. EXECUTIVE SUMMARY
o CVSS v3 7.5
o ATTENTION: Exploitable remotely/low attack complexity
o Vendor: Siemens
o Equipment: RUGGEDCOM ROX
o Vulnerability: Uncontrolled Resource Consumption
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow an unauthenticated
attacker to cause a permanent denial-of-service condition.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of RUGGEDCOM ROX, switches and serial-to-Ethernet
devices, are affected:
o RUGGEDCOM ROX MX5000: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1400: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1500: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1501: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1510: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1511: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1512: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1524: All versions prior to v2.14.1
o RUGGEDCOM ROX RX1536: All versions prior to v2.14.1
o RUGGEDCOM ROX RX5000: All versions prior to v2.14.1
3.2 VULNERABILITY OVERVIEW
3.2.1 UNCONTROLLED RESOURCE CONSUMPTION CWE-400
Affected devices write crash-dumps without checking if enough space is
available on the file system. Once the crash-dump fills the entire root file
system, affected devices fail to boot. An attacker can leverage this
vulnerability to cause a permanent denial-of-service condition.
CVE-2021-41546 has been assigned to this vulnerability. A CVSS v3 base score of
7.5 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
C:N/I:N/A:H ).
3.3 BACKGROUND
o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
3.4 RESEARCHER
Siemens reported this vulnerability to CISA.
4. MITIGATIONS
Siemens has released updates for the affected products and recommends updating
to the latest versions:
o Update to v2.14.1 or later version .
o Restrict access to the affected systems, especially to Port 443/TCP, to
trusted IP addresses only.
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 , and to
follow the recommendations in the product manuals. For additional information,
please refer to Siemens Security Advisory.
CISA 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.
CISA reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices
on the ICS webpage on us-cert.cisa.gov . 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 webpage on us-cert.cisa.gov 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 CISA for tracking
and correlation against other incidents.
No known public exploits specifically target this vulnerability.
For any questions related to this report, please contact the CISA at:
Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870
CISA 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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