Siemens Industrial Products LLDP (Update D)

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).

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 (Update C) that was published August 11, 2022, on the ICS webpage on cisa.gov/ics.

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 1542SP-1 (6GK7542-6UX00-0XE0): All versions
• SIMATIC NET CP 1542SP-1 IRC (incl. SIPLUS variants) (6GK7243-8RX30-0XE0): 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 (6GK7545-1GX00-0XE0): All versions prior to v1.1

--------- Begin Update D Part 1 of 2 ---------

• SIPLUS S7-1200 CP 1243-1 (6AG1243-1BX30-2AX0): All versions prior to v3.3.46
• SIPLUS S7-1200 CP 1243-1 RAIL (6AG2243-1BX30-1XE0): All versions prior to v3.3.46

--------- End Update D Part 1 of 2 ---------

• SIMATIC NET 1243-1 (incl. SIPLUS variants) (6GK7243-1BX30-0XE0): All versions prior to v3.3.46
• SIMATIC NET 1243-8 IRC (6GK7243-8RX30-0XE0): All versions prior to v3.3.46
• SINUMERIK ONE MCP: All versions prior to v2.0.1
• TIM 1531 IRC (incl. SIPLUS NET variants): All versions prior to v2.2

4.2 VULNERABILITY OVERVIEW

4.2.1    BUFFER COPY WITHOUT CHECKING SIZE OF INPUT (‘CLASSIC BUFFER OVERFLOW') CWE-120

A remote attacker can send specially crafted packets, which may cause a denial-of-service condition and arbitrary code execution.

CVE-2015-8011 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

4.2.2    UNCONTROLLED RESOURCE CONSUMPTION CWE-400

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.

CVE-2020-27827 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).

4.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Energy, Food and Agriculture,
  
  Water and Wastewater Systems
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Germany

4.4 RESEARCHER

Siemens reported these vulnerabilities to CISA.

5. MITIGATIONS

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
• SIMATIC NET CP 1545-1: Update to v1.1 or later

--------- Begin Update D Part 2 of 2 ---------

• SIPLUS S7-1200 CP 1243-1 (6AG1243-1BX30-2AX0): Update to v3.3.46 or later
• SIPLUS S7-1200 CP 1243-1 RAIL (6AG2243-1BX30-1XE0): Update to v3.3.46 or later

--------- End Update D Part 2 of 2 ---------

• SIMATIC CP 1243-1 (incl. SIPLUS variants) (6GK7243-1BX30-0XE0): Update to v3.3.46 or later
• SIMATIC NET CP 1243-8 IRC (6GK7243-8RX30-0XE0): Update to v3.3.46 or later
• 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

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 on the Siemens industrial security webpage.

Please see Siemens Security Advisory SSA-941426 for more information.

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

• Minimize network exposure for all control system devices and/or systems, and ensure 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 VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its 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 cisa.gov/ics 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 cisa.gov/ics 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.

• Siemens