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1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: Industrial Products
- Vulnerabilities: Classic Buffer Overflow, Uncontrolled Resource Consumption
2. UPDATE INFORMATION
This updated advisory is a follow-up to the original advisory titled ICSA-21-194-07 Siemens Industrial Products LLDP that was published July 13, 2021, to the ICS webpage on us-cert.cisa.gov.
3. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker to cause a denial-of-service condition or execute arbitrary code.
4. TECHNICAL DETAILS
4.1 AFFECTED PRODUCTS
Siemens reports these vulnerabilities affect the following products:
- SIMATIC HMI Unified Comfort Panels: All versions prior to v17
- SIMATIC NET CP 1243-1 (incl. SIPLUS variants): All versions
- SIMATIC NET CP 1243-8 IRC: All versions
- SIMATIC NET CP 1542SP-1: All versions
- SIMATIC NET CP 1542SP-1 IRC (incl. SIPLUS variants): All versions
- SIMATIC NET CP 1543-1 (incl. SIPLUS variants): All versions
- SIMATIC NET CP 1543SP-1 (incl. SIPLUS variants): All versions
- SIMATIC NET CP 1545-1: All versions
--------- Begin Update A Part 1 of 2 ---------
- SINUMERIK ONE MCP: All versions prior to v2.0.1
--------- End Update A Part 1 of 2 ---------
- TIM 1531 IRC (incl. SIPLUS NET variants): All versions prior to v2.2
4.2 VULNERABILITY OVERVIEW
A remote attacker can send specially crafted packets, which may cause a denial-of-service condition and arbitrary code execution.
A remote attacker sending specially crafted LLDP packets can cause memory to be lost when allocating data, which may cause a denial-of-service condition.
- CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Energy, Food and Agriculture,
Water and Wastewater Systems
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Germany
Siemens reported these vulnerabilities to CISA.
Siemens has released updates for the following products:
- SIMATIC HMI Unified Comfort Panels: Update to v17 or later
- TIM 1531 IRC (incl. SIPLUS NET variants): Update to v2.2 or later
--------- Begin Update A Part 2 of 2 ---------
- SINUMERIK ONE MCP: Update to v2.0.1 or later. Please contact a Siemens representative for information on how to obtain the update.
- SIMATIC NET CP 1543-1: Update to v3.0 or later
--------- End Update A Part 2 of 2 ---------
Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:
- Disable LLDP protocol support on Ethernet port. This will potentially disrupt the network visibility.
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 following the recommendations in the product manuals.
Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity
Please see Siemens Security Advisory ssa-941426 for more information.
CISA recommends 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.
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 these vulnerabilities.
For any questions related to this report, please contact the CISA at:
Toll Free: 1-888-282-0870
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