Siemens SIMATIC HMI Products

# ICS Advisory (ICSA-20-252-06) ## Siemens SIMATIC HMI Products Original release date: September 08, 2020 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-252-06) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-252-06) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-252-06) ### Legal Notice All information products included in [https://us-cert.gov/ics](/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://www.us- cert.gov/tlp/](/tlp/). * * * ## 1\. EXECUTIVE SUMMARY * **CVSS v3 6.5** * **ATTENTION:** Exploitable remotely/low skill level to exploit * **Vendor:** Siemens * **Equipment:** SIMATIC HMI * **Vulnerabilities:** Improper Restriction of Excessive Authentication Attempts, Authentication Bypass by Primary Weakness ## 2\. RISK EVALUATION Successful exploitation of these vulnerabilities could allow a remote attacker to discover user passwords and obtain access to the Sm@rt Server via a brute- force attack. ## 3\. TECHNICAL DETAILS ### 3.1 AFFECTED PRODUCTS The following versions of Siemens SIMATIC HMI Products are affected: * SIMATIC HMI Basic Panels, 2nd Generation (incl. SIPLUS variants): Version 14 and above and versions prior to XX are affected by CVE-2020-15786 * SIMATIC HMI Comfort Panels (incl. SIPLUS variants): All versions are affected by CVE-2020-15786 * SIMATIC HMI Mobile Panels: All versions are affected by CVE-2020-15786 * SIMATIC HMI United Comfort Panels: All versions ### 3.2 VULNERABILITY OVERVIEW #### 3.2.1 [IMPROPER RESTRICTION OF EXCESSIVE AUTHENTICATION ATTEMPTS CWE-307](https://cwe.mitre.org/data/definitions/307.html) Affected devices insufficiently block excessive authentication attempts. This could allow a remote attacker to discover user passwords and obtain access to the Sm@rt Server via a brute-force attack. [CVE-2020-15786](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-15786) has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is ([AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L)). #### 3.2.2 [AUTHENTICATION BYPASS BY PRIMARY WEAKNESS CWE-305](https://cwe.mitre.org/data/definitions/305.html) Affected devices insufficiently validate authentication attempts as the information given can be truncated to match only a set number of characters versus the whole provided string. This could allow a remote attacker to discover user passwords and obtain access to the Sm@rt Server via a brute- force attack. [CVE-2020-15787](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-15787) has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is ([AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)). ### 3.3 BACKGROUND * **CRITICAL INFRASTRUCTURE SECTORS:** Energy * **COUNTRIES/AREAS DEPLOYED:** Worldwide * **COMPANY HEADQUARTERS LOCATION:** Germany ### 3.4 RESEARCHER Joseph Gardiner from Bristol Cyber Security Group, University of Bristol, reported these vulnerabilities to Siemens. ## 4\. MITIGATIONS Siemens is preparing updates and recommends specific countermeasures for products where updates are not yet available. Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: * Apply defense-in-depth strategies outlined here:[ https://www.siemens.com/cert/operational-guidelines-industrial-security]( https://www.siemens.com/cert/operational-guidelines-industrial-security) As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to [Siemens operational guidelines for Industrial Security](https://www.siemens.com/cert/operational-guidelines-industrial- security) and following the recommendations in the product manuals. For additional information, please refer to Siemens Security Advisory [SSA-542525](https://cert-portal.siemens.com/productcert/pdf/SSA-542525.pdf) 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](https://www.us-cert.gov/ics/recommended-practices) on the ICS webpage on [us-cert.gov](https://www.us-cert.gov/ics). Several recommended practices are available for reading and download, including [Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies](https://www.us- cert.gov/sites/default/files/recommended_practices/NCCIC_ICS- CERT_Defense_in_Depth_2016_S508C.pdf). Additional mitigation guidance and recommended practices are publicly available on the [ICS webpage on us-cert.gov](https://www.us-cert.gov/ics) in the Technical Information Paper, [ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies](https://www.us-cert.gov/ics/tips/ICS- TIP-12-146-01B). 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.