1. EXECUTIVE SUMMARY

  • CVSS v3 7.5
  • ATTENTION: Remotely exploitable/low skill level to exploit
  • Vendor: Siemens
  • Equipment: Industrial Products
  • Vulnerability: Improper Input Validation

2. UPDATE INFORMATION

This updated advisory is a follow-up to the updated advisory titled ICSA-17-339-01 Siemens Industrial Products (Update P) published August 11, 2020, to the ICS webpage on us-cert.gov.

3. RISK EVALUATION

Successful exploitation of this vulnerability may allow a remote attacker to conduct a denial-of-service attack.

4. TECHNICAL DETAILS

4.1 AFFECTED PRODUCTS

Siemens reports the vulnerability affects the following industrial products:

  • SIMATIC S7-200 Smart: All versions prior to v2.03.01
  • SIMATIC S7-400 PN/DP v6 CPU family and below (incl. SIPLUS variants): All versions prior to v6.0.6
  • SIMATIC S7-400 H v6 CPU family and below (incl. SIPLUS variants): All versions prior to v6.0.8
  • SIMATIC S7-400 PN/DP v7 v6 CPU family (incl. SIPLUS variants): All versions prior to v7.0.2
  • SIMATIC S7-410 v8 CPU family (incl. SIPLUS variants): All versions prior to v8.2.1
  • SIMATIC S7-300 (incl. related ET200 CPUs and SIPLUS variants): All versions prior to v3.X.16
  • SIMATIC S7-1200 CPU family (incl. SIPLUS variants): All versions prior to v4.2.3
  • SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants): All versions prior to v2.0
  • SIMATIC S7-1500 Software Controller: All versions prior to v2.0
  • SIMATIC WinAC RTX (F) 2010: All versions prior to SP3
  • SIMATIC ET 200AL: All versions

——— Begin Update Q Part 1 of 1 ———

  • SIMATIC ET 200ecoPN: All versions: (except 6ES7141-6BG00-0BB0, 6ES7141-6BH00-0BB0, 6ES7142-6BG00-0BB0, 6ES7142-6BR00-0BB0, 6S7143-6BH00-0BB0, 6ES7146-6FF00-0AB0, 6ES7148-6JD00-0AB0 and 6ES7148-6JG00-0BB0)

——— End Update P Part 1 of 1 ———

  • SIMATIC ET 200M (incl. SIPLUS variants): All versions
  • SIMATIC ET 200MP IM155-5 PN BA (incl. SIPLUS variants): All versions prior to v4.0.2
  • SIMATIC ET 200MP IM155-5 PN ST (incl. SIPLUS variants): All versions prior to v4.1
  • SIMATIC ET 200MP IM155-5 PN HF (incl. SIPLUS variants): All versions prior to v4.2
  • SIMATIC ET 200pro: All versions
  • SIMATIC ET 200S (incl. SIPLUS variants): All versions
  • SIMATIC ET 200SP IM 155-6 PN HF (incl. SIPLUS variants): All versions prior to v4.2.0
  • SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants): All versions prior to v1.1.0
  • SIMATIC ET 200SP IM 155-6 PN BA (incl. SIPLUS variants): All versions
  • SIMATIC ET 200SP IM 155-6 PN ST (incl. SIPLUS variants): All versions
  • SIMATIC ET 200SP IM 155-6 PN HS (incl. SIPLUS variants): All versions
  • SIMATIC TDC CPU555: All versions prior to v1.1.1
  • SIMATIC TDC CP51M1: All versions prior to v1.1.8
  • Development/Evaluation Kits for PROFINET IO: DK Standard Ethernet Controller: All versions prior to v4.1.1 Patch 05
  • Development/Evaluation Kits for PROFINET IO: EK-ERTEC 200P: All versions prior to v4.5
  • Development/Evaluation Kits for PROFINET IO: EK-ERTEC 200: All versions prior to v4.5
  • SIMOTION D (incl. SIPLUS variants): All versions prior to v5.1 HF1
  • SIMOTION C: All versions prior to v5.1 HF1
  • SIMOTION P v4.4 and v4.5: All versions prior to v4.5 HF5
  • SIMOTION P v5: All versions prior to v5.1 HF1
  • SINAMICS DCM w. PN: All versions prior to v1.4 SP1 HF6
  • SINAMICS DCP w. PN: All versions prior to v1.2 HF2
  • SINAMICS G110M w. PN: All versions prior to v4.7 SP9 HF1
  • SINAMICS G120(C/P/D) w. PN (incl. SIPLUS variants): All versions prior to v4.7 SP9 HF1
  • SINAMICS G130 v4.7 w. PN: All versions prior to v4.7 HF29
  • SINAMICS G130 v4.8 w. PN: All versions prior to v4.8 HF4
  • SINAMICS G150 v4.7 w. PN: All versions prior to v4.7 HF29
  • SINAMICS G150 v4.8 w. PN: All versions prior to v4.8 HF4
  • SINAMICS S110 w. PN: All versions prior to v4.4 SP3 HF6
  • SINAMICS S120 prior to v4.7 w. PN (incl. SIPLUS variants): All versions prior to v4.7
  • SINAMICS S120 v4.7 w. PN (incl. SIPLUS variants): All versions prior to v4.7 HF29
  • SINAMICS S120 v4.7 SP1 w. PN (incl. SIPLUS variants): All versions
  • SINAMICS S120 v4.8 w. PN: All versions prior to v4.8 HF5
  • SINAMICS S150 V4.7 w. PN: All versions prior to v4.7 HF29
  • SINAMICS S150 V4.8 w. PN:All versions prior to v4.8 HF4
  • SINAMICS v90 w. PN: All versions prior to v1.02
  • SINUMERIK 840D sl: All versions prior to 4.8 SP3
  • SIMATIC Compact Field Unit: All versions
  • SIMATIC PN/PN Coupler (incl. SIPLUS NET variants): All versions prior to v4.2.0
  • SIMOCODE pro V PN (incl. SIPLUS variants): All versions prior to v2.1.1
  • SIRIUS Soft starter 3RW44 PN: All versions

4.2 VULNERABILITY OVERVIEW

4.2.1 IMPROPER INPUT VALIDATION CWE-20

Specially crafted packets sent to Port 161/UDP could cause a denial-of-service condition. The affected devices must be restarted manually.

CVE-2017-12741 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; 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: Commercial Facilities, Critical Manufacturing, Energy, Food and Agriculture, Water and Wastewater Systems
  • Countries/Areas Deployed: Worldwide
  • Company Headquarters Location: Germany

4.4 RESEARCHER

George Lashenko of CyberX reported the vulnerability to Siemens.

5. MITIGATIONS

Siemens has provided firmware updates for the following products to fix the vulnerability:

Siemens is preparing further updates and recommends the following mitigations until patches are available:

  • Disable SNMP if this is supported by the product (refer to the product documentation). Disabling SNMP fully mitigates the vulnerability
  • Protect network access to Port 161/UDP of affected devices
  • Apply cell protection concept
  • Use VPN for protecting network communication between cells
  • Apply defense-in-depth

Siemens recommends users configure the operational environment according to Siemens’ Operational Guidelines for Industrial Security.

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.

Source:

https://us-cert.cisa.gov/ics/advisories/ICSA-17-339-01