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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.3559 Advisory (icsa-19-260-02) Siemens SINEMA Remote Connect Server 20 September 2019 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SINEMA Remote Connect Server Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Access Privileged Data -- Remote with User Interaction Cross-site Request Forgery -- Remote with User Interaction Resolution: Patch/Upgrade CVE Names: CVE-2019-34623 CVE-2019-13922 CVE-2019-13920 CVE-2019-13918 Original Bulletin: https://www.us-cert.gov/ics/advisories/icsa-19-260-02 - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-19-260-02) Siemens SINEMA Remote Connect Server Original release date: September 17, 2019 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/ . 1. EXECUTIVE SUMMARY o CVSS v3 8.1 o ATTENTION: Exploitable remotely o Vendor: Siemens o Equipment: SINEMA Remote Connect Server o Vulnerabilities: Improper Restriction of Excessive Authentication Attempts, Information Exposure, Cross-Site Request Forgery, Use of Password Hash with Insufficient Computational Effort 2. RISK EVALUATION Successful exploitation of these vulnerabilities may allow an attacker unauthorized access to the web interface, improper access to privileged user and device information, and may allow successful CSRF attacks. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following versions of SINEMA Remote Connect Server are affected: o SINEMA Remote Connect Server versions prior to 2.0 SP1 3.2 VULNERABILITY OVERVIEW 3.2.1 IMPROPER RESTRICTION OF EXCESSIVE AUTHENTICATION ATTEMPTS CWE-307 The web interface has no means to prevent password guessing attacks. This vulnerability could be exploited by an attacker with network access to the vulnerable software, requiring no privileges and no user interaction. Exploitation could allow full access to the web interface. CVE-2019-13918 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:N/UI:N/S:U/ C:H/I:H/A:H ). 3.2.2 INFORMATION EXPOSURE CWE-200 Some pages that should only be accessible by a privileged user can also be accessed by a nonprivileged user. This vulnerability could be exploited by an attacker with network access and valid credentials for the web interface. No user interaction is required. Exploitation could allow an attacker to access information they should not be able to read. The information affected by this vulnerability does not include passwords. CVE-2019-34623 has been assigned to this vulnerability. A CVSS v3 base score of 4.3 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:N/S:U/ C:L/I:N/A:N ). 3.2.3 CROSS-SITE REQUEST FORGERY CWE-352 Some parts of the web application are not protected against cross-site request forgery (CSRF) attacks. This vulnerability could be exploited by an attacker who is able to trigger requests of a logged-in user to the application. Exploitation could allow switching the connectivity state of a user or a device. CVE-2019-13920 has been assigned to this vulnerability. A CVSS v3 base score of 3.4 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:N/UI:R/S:C/ C:N/I:L/A:N ). 3.2.4 USE OF PASSWORD HASH WITH INSUFFICIENT COMPUTATIONAL EFFORT CWE-916 An attacker with administrative privileges can obtain the hash of a connected device's password. The security vulnerability could be exploited by an attacker with network access to the SINEMA Remote Connect Server and administrative privileges. CVE-2019-13922 has been assigned to this vulnerability. A CVSS v3 base score of 6.6 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:H/UI:N/S:C/ C:N/I:L/A:H ). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Agriculture and Food, Chemical, Critical Manufacturing Energy, Water and Wastewater Systems o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Hendrik Derre and Tijl Deneut from HOWEST reported these vulnerabilities to Siemens. 4. MITIGATIONS Siemens recommends users upgrade to Versions 2.0 SP1 or later for the affected products. The v2.0 SP1 update can be obtained at the following location: https://support.industry.siemens.com/cs/ww/en/view/109770899 For more information on these vulnerabilities and associated software updates, please see Siemens' security advisory SSA-884497 at: https://www.siemens.com/ cert/advisories . Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: o Restrict network access to the SINEMA Remote Connect web interface o Do not access links from untrusted sources while logged in at SINEMA Remote Connect CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should: o Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet . o Locate control system networks and remote devices behind firewalls, and isolate them from the business network. 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 on the ICS webpage on us-cert.gov . 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 on the ICS webpage on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies . 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. High skill level is needed to exploit. - --------------------------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 auscert@auscert.org.au 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: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au 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 iQIVAwUBXYRaKGaOgq3Tt24GAQihLg//SDecRE2TMUEgR2aGPGqRs874lq+cZGWD YW1WOoHCP2UEu6u7K0rQVibvZEVbfLEUiDko3B23nJiUcZFeUv/h/lSaYeYJLV+n Qme+XiwjBfRYG0bYCTx/6oaZenkT2KgXNAUEX5LMWQq1ay95DzJSGhebsS6PMpNQ 3RzoDAs2GaoDoV8e0JwFsDub0TJiIpGmjnF+5pdoOEZE94wR6E1/MvDR92Zd+Nwy bHgmZY30NU/+jQRzPXlJq0k6xX88/30aq3pPSmiAGa/34zPaHbEGpCm4edskD80U /s5aEXDko0Uru7iF0R5B0qQJJrz1tNZPTueGtTpYS206kDG9U1ZwZyOWnTdXLqd9 gLge/MAz6hJ7hoMrMOi155r77XiKrHpRqi3Plo38yI87lBxE2hdO7XLROu1LtWpp Isqycfp76FIW+YCT98pURz3MKPSaZOErH5UekFe9TshAcGaLb+BQmCmj+YR28ATn AOSRgqlVJ+ltSPxoJb7RdFt6OU1Fkyp5RUS2TfhyLhxeWlpc8EvQSdHIWKnRef3A UFjleTOTVXo5R29w1oGFLDzC0v9fLvjj7riVkvsnqdojImyVnOs5jtLlCpY8RDqe JXFXGpeLEYR793pw5Gdrs4ambNUQEbcn4DHR7lLs5i9icm0E7g2nk67c60vimdhi iVc7LrJEeOU= =x7+o -----END PGP SIGNATURE-----