Schneider Electric Modicon Premium, Modicon Quantum, Modicon M340, and Modicon BMXNOR0200 Stack-based Buffer Overflow, Use of Hard-coded (CVE-2018-7242 CVE-2018-7241 CVE-2018-7240 )

# ICS Advisory (ICSA-18-086-01) ## Schneider Electric Modicon Premium, Modicon Quantum, Modicon M340, and Modicon BMXNOR0200 Original release date: March 27, 2018 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-086-01) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-086-01) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-086-01) ### 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/). * * * ### **CVSS v3 5.9** **ATTENTION:** Exploitable remotely/low skill level to exploit. **Vendor:** Schneider Electric **Equipment:** Modicon Premium, Modicon Quantum, Modicon M340, and Modicon BMXNOR0200 **Vulnerabilities:** Stack-based Buffer Overflow, Use of Hard-coded Credentials, Use of a Broken or Risky Cryptographic Algorithm. ## AFFECTED PRODUCTS The following versions of Modicon PLCs are affected: * Modicon Premium all versions, * Modicon Quantum all versions, * Modicon M340 all versions, and * Modicon X80 RTU (BMXNOR0200H) all versions. ## IMPACT Successful exploitation of these vulnerabilities could allow a remote unauthorized attacker access to the file transfer service on the device, which could result in arbitrary code execution or malicious firmware installation. ## MITIGATION Schneider Electric recommends that users follow the instructions outlined in the [Modicon Controllers Platform - Cyber Security, Reference Manual](https://www.schneider- electric.com/en/download/document/EIO0000001999/) to install Modicon PLCs securely. Schneider Electric also recommends that affected users disable FTP services on the device during times when maintenance or configuration activities are not needed. For more information please see Schneider Electric's security notification SEVD-2018-081-01 at: <https://www.schneider-electric.com/en/download/document/SEVD-2018-081-01/> NCCIC recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should: * Minimize network exposure for all control system devices and/or systems, and ensure that they are [not accessible from the Internet](/ics/alerts/ICS-ALERT-10-301-01). * Locate control system networks and remote devices behind firewalls, and isolate them from the business network. * When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices. NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. NCCIC also provides a section for [control systems security recommended practices](/ics/content/recommended-practices) on the ICS-CERT web page. Several recommended practices are available for reading and download, including [Improving Industrial Control Systems Cybersecurity with Defense-in- Depth Strategies.](/sites/default/files/recommended_practices/NCCIC_ICS- CERT_Defense_in_Depth_2016_S508C.pdf) Additional mitigation guidance and recommended practices are publicly available in the NCCIC Technical Information Paper, [ICS-TIP-12-146-01B-- Targeted Cyber Intrusion Detection and Mitigation Strategies](/ics/tips/ICS- TIP-12-146-01B), that is available for download from the [ICS-CERT website](/ics/). Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents. No known public exploits specifically target these vulnerabilities. ## VULNERABILITY OVERVIEW ## [STACK-BASED BUFFER OVERFLOW CWE-121](https://cwe.mitre.org/data/definitions/121.html) The FTP server does not limit the length of a command parameter which may cause a buffer overflow condition. [CVE-2018-7240](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7240) has been assigned to this vulnerability. A CVSS v3 base score of 4.8 has been calculated; the CVSS vector string is ([AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H)). ## [USE OF HARD-CODED CREDENTIALS CWE-798](https://cwe.mitre.org/data/definitions/798.html) The FTP servers contain a hard-coded account, which could allow unauthorized access. [CVE-2018-7241](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7241) has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is ([AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H)). ## [USE OF A BROKEN OR RISKY CRYPTOGRAPHIC ALGORITHM CWE-327](https://cwe.mitre.org/data/definitions/327.html) The FTP server does not limit the length of a command parameter, which may cause a buffer overflow condition. [CVE-2018-7242](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7242) has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is ([AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H)). ## RESEARCHER Nikita Maximov, Alexey Stennikov, and Kirill Chernyshov of Positive Technologies reported the vulnerabilities to Schneider Electric. Meng Leizi and Zhang Daoquan reported the vulnerabilities to NCCIC. ## BACKGROUND **Critical Infrastructure Sector:** Critical Manufacturing **Countries/Areas Deployed:** Worldwide **Company Headquarters Location:** France