GAIN Electronic Co. Ltd SAGA1-L Series Authentication Bypass by Capture-replay, Improper Access Control, Improper Authentication (CVE-2018-17923 CVE-2018-17921 CVE-2018-17903 )

# ICS Advisory (ICSA-18-296-02) ## GAIN Electronic Co. Ltd SAGA1-L Series Original release date: October 23, 2018 | Last revised: October 25, 2018 [Print Document](javascript:window.print\(\);) [Tweet](https://twitter.com/share?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-296-02) [Like Me](https://www.facebook.com/sharer.php?u=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-296-02) [Share](http://www.addthis.com/bookmark.php?url=https%3A%2F%2Fus- cert.cisa.gov%2Fics%2Fadvisories%2FICSA-18-296-02) ### 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 8.3** * **ATTENTION:** Exploitable from an adjacent network/low skill level to exploit * **Vendor:** GAIN Electronic Co. Ltd * **Equipment:** SAGA1-L series * **Vulnerabilities:** Authentication Bypass by Capture-replay, Improper Access Control, Improper Authentication ## 2\. RISK EVALUATION Successful exploitation of these vulnerabilities could allow remote code execution and potentially delete the product's firmware. ## 3\. TECHNICAL DETAILS ### 3.1 AFFECTED PRODUCTS According to GAIN Electronic Co. Ltd, the following product is affected: * SAGA1-L8B: All firmware versions prior to A0.10 ### 3.2 VULNERABILITY OVERVIEW **3.2.1 [AUTHENTICATION BYPASS BY CAPTURE-REPLAY CWE-294](https://cwe.mitre.org/data/definitions/294.html)** This product is vulnerable to a replay attack and command forgery. [CVE-2018-17903](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-17903) has been assigned to this vulnerability. A CVSS v3 base score of 8.3 has been calculated; the CVSS vector string is ([AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H)). **3.2.2 [IMPROPER ACCESS CONTROL CWE-284](https://cwe.mitre.org/data/definitions/284.html)** This vulnerability may allow an attacker to force-pair the device without human interaction. [CVE-2018-17921](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-17921) has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is ([AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)). **3.2.3 [IMPROPER AUTHENTICATION CWE-287](https://cwe.mitre.org/data/definitions/287.html)** An attacker with physical access to the product may able to reprogram it. [CVE-2018-17923](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-17923) has been assigned to this vulnerability. A CVSS v3 base score of 6.1 has been calculated; the CVSS vector string is ([AV:P/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:P/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H)). ### 3.3 BACKGROUND * **CRITICAL INFRASTRUCTURE SECTORS:** Communications * **COUNTRIES/AREAS DEPLOYED:** United States * **COMPANY HEADQUARTERS LOCATION:** Taiwan ### 3.4 RESEARCHER Marco Balduzzi, Philippe Z Lin, Federico Maggi, Jonathan Andersson, Urano Akira, Stephen Hilt, and Rainer Vosseler working with Trend Micro's Zero Day Initiative reported these vulnerabilities to NCCIC. ## 4\. MITIGATIONS GAIN Electronic Co. Ltd has recommended that users update to firmware version A0.10. The new firmware can be obtained through a distributor. NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should ensure the product is in a physically secure area. 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 these vulnerabilities.