Fr. Sauter AG CASE Suite Improper Restriction of XML External Entity Reference (CVE-2018-17912)

# ICS Advisory (ICSA-18-305-04 ) ## Fr. Sauter AG CASE Suite Original release date: November 01, 2018 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-305-04) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-305-04) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-305-04) ### 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/low skill level to exploit * **Vendor:** Fr. Sauter AG * **Equipment:** CASE Suite * **Vulnerability:** Improper Restriction of XML External Entity Reference ## 2\. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker to remotely retrieve unauthorized files from the system. ## 3\. TECHNICAL DETAILS ### 3.1 AFFECTED PRODUCTS The following versions of CASE Suite are affected: * CASE Suite Versions 3.10 and prior. ### 3.2 VULNERABILITY OVERVIEW **3.2.1 [IMPROPER RESTRICTION OF XML EXTERNAL ENTITY REFERENCE ('XXE') CWE-611](https://cwe.mitre.org/data/definitions/611.html)** An XXE vulnerability exists when processing parameter entities, which may allow remote file disclosure. [CVE-2018-17912](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-17912) has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is ([AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)). ### 3.3 BACKGROUND * **CRITICAL INFRASTRUCTURE SECTORS:** Critical Manufacturing * **COUNTRIES/AREAS DEPLOYED:** Worldwide * **COMPANY HEADQUARTERS LOCATION:** Switzerland ### 3.4 RESEARCHER Gjoko Krstic of Applied Risk reported this vulnerability to NCCIC. ## 4\. MITIGATIONS Fr. Sauter AG recommends users apply Service Release 1 for the current CASE Suite Version 3.10. The software is deployed via local support channels. NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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 on the [ICS-CERT website](/ics/) in the Technical Information Paper, [ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies](/ics/tips/ICS-TIP-12-146-01B). 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 this vulnerability.