WECON LeviStudioU （CVE-2020-25186 CVE-2020-16243）

# ICS Advisory (ICSA-20-238-03) ## WECON LeviStudioU (Update A) Original release date: October 20, 2020 | Last revised: October 21, 2020 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-238-03) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-238-03) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2Ficsa-20-238-03) ### 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 7.8** * **ATTENTION:** Low skill level to exploit * **Vendor:** WECON Technology Co., Ltd (WECON) * **Equipment:** LeviStudioU **\--------- Begin Update A Part 1 of 4 ---------** * **Vulnerabilities** : Stack-based Buffer Overflow, Improper Restriction of XML External Entity Reference **\--------- End Update A Part 1 of 4 ---------** ## 2\. UPDATE INFORMATION This updated advisory is a follow-up to the original advisory titled ICSA-20-238-03 WECON LeviStudioU that was published August 25, 2020, to the ICS webpage on us-cert.cisa.gov. ## 3\. RISK EVALUATION **\--------- Begin Update A Part 2 of 4 ---------** Successful exploitation of these vulnerabilities could allow an attacker to execute code under the privileges of the application and obtain sensitive information. **\--------- End Update A Part 2 of 4 ---------** ## 4\. TECHNICAL DETAILS ### 4.1 AFFECTED PRODUCTS The following versions of LeviStudioU are reported to be affected: * LeviStudioU: Release Build 2019-09-21 and prior. If you have questions about the affected products, please contact WECON. ### 4.2 VULNERABILITY OVERVIEW #### 4.2.1 [STACK-BASED BUFFER OVERFLOW CWE-121](https://cwe.mitre.org/data/definitions/121.html) Multiple buffer overflow vulnerabilities exist when processing project files. Opening a specially crafted project file could allow an attacker to exploit and execute code under the privileges of the application. [CVE-2020-16243](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-16243) has been assigned to these vulnerabilities. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is ([AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)). **\--------- Begin Update A Part 3 of 4 ---------** #### 4.2.2 [IMPROPER RESTRICTION OF XML EXTERNAL ENTITY REFERENCE CWE-611](https://cwe.mitre.org/data/definitions/611.html) An XXE vulnerability exists when processing parameter entities, which may allow file disclosure. [CVE-2020-25186](https://nvd.nist.gov/vuln/detail/CVE-2020-25186) has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is ([AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)). **\--------- End Update A Part 3 of 4 ---------** ### 4.3 BACKGROUND * **CRITICAL INFRASTRUCTURE SECTORS:** Critical Manufacturing, Energy, Water and Wastewater Systems * **COUNTRIES/AREAS DEPLOYED:** Worldwide * **COMPANY HEADQUARTERS LOCATION:** China ### 4.4 RESEARCHER **\--------- Begin Update A Part 4 of 4 ---------** Natnael Samson and Mehmet D. INCE @mdisec from T0.Group, working with Trend Micro's Zero Day Initiative, reported these vulnerabilities to CISA. **\--------- End Update A Part 4 of 4 ---------** ## 5\. MITIGATIONS WECON is aware of the issue and is currently developing a solution. For more information, [contact WECON online](http://www.we-con.com.cn/en/message.html) or by phone: 0086-591-87868869-894 CISA recommends users take the following measures to protect themselves from social engineering attacks: * Only use project files from trusted sources. * Do not click web links or open unsolicited attachments in email messages. * Refer to [Recognizing and Avoiding Email Scams](https://us-cert.cisa.gov/sites/default/files/publications/emailscams_0905.pdf) for more information on avoiding email scams. * Refer to [Avoiding Social Engineering and Phishing Attacks](https://us-cert.cisa.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.cisa.gov](https://www.us-cert.cisa.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.cisa.gov](https://www.us- cert.cisa.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. These vulnerabilities are not exploitable remotely.