15 July 2016
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.1755 Moxa MGate Authentication Bypass Vulnerability 15 July 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Moxa MGate Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Access Privileged Data -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2016-5804 Original Bulletin: http://ics-cert.us-cert.gov/advisories/ICSA-16-196-02 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-16-196-02) Moxa MGate Authentication Bypass Vulnerability Original release date: July 14, 2016 Legal Notice All information products included in http://ics-cert.us-cert.gov 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 http://www.us-cert.gov/tlp/. OVERVIEW Independent researcher Maxim Rupp has identified an authentication bypass vulnerability in Moxas MGate products. Moxa has produced new firmware versions to mitigate this vulnerability. This vulnerability could be exploited remotely. AFFECTED PRODUCTS Moxa reports that the vulnerability affects the following products: MGate MB3180, versions prior to v1.8, MGate MB3280, versions prior to v2.7, MGate MB3480, versions prior to v2.6, MGate MB3170, versions prior to v2.5, and MGate MB3270, versions prior to v2.7 IMPACT A successful exploit of this vulnerability may allow an attacker to log in as a valid user. Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation. BACKGROUND Moxa is a Taiwan-based company that maintains offices in several countries around the world, including the US, UK, India, Germany, France, China, Russia, and Brazil. The affected product, MGate, is a serial to Ethernet modbus gateway. According to Moxa, MGate is deployed across several sectors, including Chemical, Commercial Facilities, Critical Manufacturing, Emergency Services, Energy, Food and Agriculture, Government Facilities, and Water and Wastewater Systems. Moxa estimates that this product is used globally but concentrated in the US, Europe, South America, and Taiwan. VULNERABILITY CHARACTERIZATION VULNERABILITY OVERVIEW INADEQUATE ENCRYPTION STRENGTH [a] An attacker can use accessible information to brute force a parameter that will allow a bypass of authentication mechanisms. CVE-2016-5804 [b] has been assigned to this vulnerability. A CVSS v3 base score of 9.1 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N). [c] VULNERABILITY DETAILS EXPLOITABILITY This vulnerability could be exploited remotely. EXISTENCE OF EXPLOIT No known public exploits specifically target this vulnerability. DIFFICULTY An attacker with a low skill would be able to exploit this vulnerability. MITIGATION Moxa has released new versions of firmware, which has enhanced the security of the MB3x70 and MB3x80 families. This new firmware can be located on its web site at the following locations: MB3180, v1.8, MB3280, v2.7, and MB3480, v2.6 http://www.moxa.com/support/sarch_result.aspx?type=soft&prod_id=73&type_id=4 (link is external) MB3170, v2.5 and MB3270, v2.7 http://www.moxa.com/support/sarch_result.aspx?type=soft&prod_id=74&type_id=4 (link is external) ICS-CERT recommends that 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. 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. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT web page at: http://ics-cert.us-cert.gov/content/recommended-practices. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. Additional mitigation guidance and recommended practices are publicly available in the ICSCERT Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site (http://ics-cert.us-cert.gov/). Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to ICS-CERT for tracking and correlation against other incidents. a. CWE-326: Inadequate Encryption Strength, http://cwe.mitre.org/data/definitions/326.html, web site last accessed July 14, 2016. b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-5804, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. c. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S..., web site last accessed July 14, 2016. Contact Information For any questions related to this report, please contact ICS-CERT at: Email: firstname.lastname@example.org (link sends e-mail) Toll Free: 1-877-776-7585 International Callers: (208) 526-0900 For industrial control systems security information and incident reporting: http://ics-cert.us-cert.gov ICS-CERT continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to email@example.com and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: firstname.lastname@example.org Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBV4h0kYx+lLeg9Ub1AQiZlw/6AqnPeF9E3fWycPbONVDXLD0jqlqR7e8z ymHdHvwmOG/R5oAoeZAZC1qvO+UkSkTyWlvY5PwM2W94U7F4ajQAu3V01kUdRSmk d9rNLi5P+5bq4y/phnGi4hbeIMwE5LJ3TuFgyFLZuTPpVE/rsjaFSTOvQa6CQPnz M0iBw5vD1Gulh3eogOoieJGZHNnc/PnMysn3ssuCxCG81NITKCH9ZFzlsbiGdJVK S2QW2pLqBASAh0ehNLe7k4ECj5TNh4S3hJIYTxPBM7UfHiv2teMvw7KmlCRaI6Hg OrcLsEEJive31EblRh2MQrKM24gqTWOr70Ht4qZoUv71Bdmf/bOtpLoX0fDjp37F R9fSgDGOTLrDz/vocFo8tSAv06k5dE4xh6TrzClA29WU+1d2aPybTkPbKhETM088 QsYgJVWuS5782Vxox93/lJxHqTWayL2hXS2Yn9K5+fkbq9rhiz4/lN6VnNk6W2fU R3nByh+s45WUuxZrjfcIUhX3oqWh0mY5wlhq2oFnVORP1IR455owUYOWr9jaBNyQ SmSVBlIxsnBJ5eKTwvGD5cCXBX8/zMbOBknvOphQ34Pju2VAsmy9bT05tLqI0GXD MMok6qAbgaI5DbbkDo274JlJjbACwwY+uhhFtebJWuYIpRpIS34jCpMQPK2roQCc pJAqssXPnMU= =Lk7g -----END PGP SIGNATURE-----