-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 # SSA-549234: Denial-of-Service Vulnerability in SIMATIC NET CP Modules Publication Date: 2021-09-14 Last Update: 2023-04-11 Current Version: 1.3 CVSS v3.1 Base Score: 7.5 SUMMARY ======= A denial of service vulnerability was identified in different types of Communication Processors. An attacker could exploit this vulnerability causing the device to become un-operational until the device is restarted. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not, or not yet available. AFFECTED PRODUCTS AND SOLUTION ============================== * SIMATIC CP 343-1 (incl. SIPLUS variants) - Affected versions: All versions - Remediation: Currently no fix is planned See recommendations from section "Workarounds and Mitigations" * SIMATIC CP 343-1 Advanced (incl. SIPLUS variants) - Affected versions: All versions - Remediation: Currently no fix is planned See recommendations from section "Workarounds and Mitigations" * SIMATIC CP 343-1 ERPC (6GK7343-1FX00-0XE0) - Affected versions: All versions - Remediation: Currently no fix is planned See recommendations from section "Workarounds and Mitigations" * SIMATIC CP 343-1 Lean (incl. SIPLUS variants) - Affected versions: All versions - Remediation: Currently no fix is planned See recommendations from section "Workarounds and Mitigations" * SIMATIC CP 443-1 (6GK7443-1EX30-0XE0) - Affected versions: All versions < V3.3 - Remediation: Update to V3.3 or later version See recommendations from section "Workarounds and Mitigations" - Download: https://support.industry.siemens.com/cs/ww/en/view/109817938/ * SIMATIC CP 443-1 (6GK7443-1EX30-0XE1) - Affected versions: All versions < V3.3 - Remediation: Update to V3.3 or later version See recommendations from section "Workarounds and Mitigations" - Download: https://support.industry.siemens.com/cs/ww/en/view/109817938/ * SIMATIC CP 443-1 Advanced (6GK7443-1GX30-0XE0) - Affected versions: All versions < V3.3 - Remediation: Update to V3.3 or later version See recommendations from section "Workarounds and Mitigations" - Download: https://support.industry.siemens.com/cs/ww/en/view/109817938/ * SIPLUS NET CP 443-1 (6AG1443-1EX30-4XE0) - Affected versions: All versions < V3.3 - Remediation: Update to V3.3 or later version See recommendations from section "Workarounds and Mitigations" - Download: https://support.industry.siemens.com/cs/ww/en/view/109817938/ * SIPLUS NET CP 443-1 Advanced (6AG1443-1GX30-4XE0) - Affected versions: All versions < V3.3 - Remediation: Update to V3.3 or later version See recommendations from section "Workarounds and Mitigations" - Download: https://support.industry.siemens.com/cs/ww/en/view/109817938/ WORKAROUNDS AND MITIGATIONS =========================== Siemens has identified the following specific workarounds and mitigations that customers can apply to reduce the risk: * Limit access to port 102/tcp to trusted users and systems only Product-specific remediations or mitigations can be found in the section "Affected Products and Solution". Please follow the "General Security Recommendations". GENERAL SECURITY RECOMMENDATIONS ================================ As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens' operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial- security), and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity PRODUCT DESCRIPTION =================== SIMATIC CP 343-1 and CP 443-1 are communication processors (CP) designed to enable Ethernet communication for SIMATIC S7-300/S7-400 CPUs. SIPLUS extreme products are designed for reliable operation under extreme conditions and are based on SIMATIC, LOGO!, SITOP, SINAMICS, SIMOTION, SCALANCE or other devices. SIPLUS devices use the same firmware as the product they are based on. VULNERABILITY CLASSIFICATION ============================ The vulnerability classification has been performed by using the CVSS scoring system in version 3.1 (CVSS v3.1) (https://www.first.org/cvss/). The CVSS environmental score is specific to the customer's environment and will impact the overall CVSS score. The environmental score should therefore be individually defined by the customer to accomplish final scoring. An additional classification has been performed using the CWE classification, a community-developed list of common software security weaknesses. This serves as a common language and as a baseline for weakness identification, mitigation, and prevention efforts. A detailed list of CWE classes can be found at: https://cwe.mitre.org/. * Vulnerability CVE-2021-33737 Sending a specially crafted packet to port 102/tcp of an affected device could cause a denial of service condition. A restart is needed to restore normal operations. CVSS v3.1 Base Score: 7.5 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:U/RC:C CWE: CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer ACKNOWLEDGMENTS =============== Siemens thanks the following party for its efforts: * Michael Messner from Siemens Energy for reporting the vulnerability ADDITIONAL INFORMATION ====================== For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories HISTORY DATA ============ V1.0 (2021-09-14): Publication Date V1.1 (2021-12-14): Specifically added that SIMATIC CP 343-1 devices do not have any fix planned V1.2 (2022-06-14): Specifically added that SIMATIC CP 443-1 Advanced devices do not have any fix planned V1.3 (2023-04-11): Added fix for SIMATIC CP 443-1 and CP 443-1 Advanced TERMS OF USE ============ Siemens Security Advisories are subject to the terms and conditions contained in Siemens' underlying license terms or other applicable agreements previously agreed to with Siemens (hereinafter "License Terms"). To the extent applicable to information, software or documentation made available in or through a Siemens Security Advisory, the Terms of Use of Siemens' Global Website (https://www.siemens.com/terms_of_use, hereinafter "Terms of Use"), in particular Sections 8-10 of the Terms of Use, shall apply additionally. In case of conflicts, the License Terms shall prevail over the Terms of Use. 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