Siemens SIMATIC S7-1500 (Update A)

# ICS Advisory (ICSA-20-042-11) ## Siemens SIMATIC S7-1500 (Update A) Original release date: March 10, 2020 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-042-11) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-042-11) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-042-11) ### 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 7.5** * **ATTENTION:** Exploitable remotely * **Vendor:** Siemens * **Equipment:** SIMATIC S7-1500 CPU family * **Vulnerability:** Resource Exhaustion ## 2\. UPDATE INFORMATION This updated advisory is a follow-up to the original advisory titled ICSA-20-042-11 Siemens SIMATIC S7-1500 that was published February 11, 2020, to the ICS webpage on us-cert.gov. ## 3\. RISK EVALUATION This vulnerability could allow a remote attacker to conduct denial-of-service attacks. ## 4\. TECHNICAL DETAILS ### 4.1 AFFECTED PRODUCTS The following versions of SIMATIC are affected: * SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants): All versions **\--------- Begin Update A Part 1 of 2 ---------** * SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants): All versions v2.5 or higher and lower than v20.8 **\--------- End Update A Part 1 of 2 ---------** * SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants): All versions v2.5 or higher and lower than v2.8 * SIMATIC S7-1500 Software Controller: All versions v2.5 or higher and lower than v20.8 ### 4.2 VULNERABILITY OVERVIEW #### 4.2.1 [UNCONTROLLED RESOURCE CONSUMPTION ('RESOURCE EXHAUSTION') CWE-400](https://cwe.mitre.org/data/definitions/400.html) Affected devices contain a vulnerability that allows an unauthenticated attacker to trigger a denial-of-service condition. The vulnerability can be triggered if specially crafted UDP packets are sent to the device. [CVE-2019-19281](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-19281) 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](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)). ### 4.3 BACKGROUND * **CRITICAL INFRASTRUCTURE SECTORS:** Critical Manufacturing * **COUNTRIES/AREAS DEPLOYED:** Worldwide * **COMPANY HEADQUARTERS LOCATION:** Germany ### 4.4 RESEARCHER Siemens reported this vulnerability to CISA. ## 5\. MITIGATIONS **\--------- Begin Update A Part 2 of 2 ---------** Siemens has released updates for several affected products and recommends specific workarounds and mitigations that customers can apply to reduce the risk: * Restrict network access to affected devices. * For SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants), Siemens recommends users [update to v20.8](https://support.industry.siemens.com/cs/ww/en/view/109759122) (v2x.8 corresponds to v2.8 of the S7-1500 CPU firmware). **\--------- End Update A Part 2 of 2 ---------** * For SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants), Siemens recommends users [update to v2.8](https://support.industry.siemens.com/cs/ww/en/view/109773807) * For SIMATIC S7-1500 Software Controller, Siemens recommends users [update to v20.8](https://support.industry.siemens.com/cs/de/en/view/109772864) (v2x.8 corresponds to v2.8 of the S7-1500 CPU firmware). For more information on this vulnerability and associated software updates, please see Siemens security advisory [SSA-750824](https://www.siemens.com/cert/advisories) CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should protect themselves from social engineering attacks: * Do not click web links or open unsolicited attachments in email messages. * Refer to [Recognizing and Avoiding Email Scams](https://www.us-cert.gov/sites/default/files/publications/emailscams_0905.pdf) for more information on avoiding email scams. * Refer to [Avoiding Social Engineering and Phishing Attacks](https://www.us-cert.gov/ncas/tips/ST04-014) for more information on social engineering attacks. 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 this vulnerability.