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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.1752 Advisory (ICSA-18-163-02) Siemens SCALANCE X Switches 13 June 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SCALANCE X Switches Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Cross-site Scripting -- Remote with User Interaction Resolution: Patch/Upgrade CVE Names: CVE-2018-4848 CVE-2018-4842 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-18-163-02 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-18-163-02) Siemens SCALANCE X Switches Original release date: June 12, 2018 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 5.8 o ATTENTION: Exploitable remotely o Vendor: Siemens o Equipment: SCALANCE X switches o Vulnerabilities: Cross-site Scripting 2. RISK EVALUATION Successful exploitation of these cross-site scripting vulnerabilities could allow an attacker to store script code on the website and execute cross-site scripting (XSS), affecting the website's confidentiality, integrity, and availability. However, no known public exploits specifically target these vulnerabilities. High skill level is needed to exploit. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS Siemens reports the vulnerabilities affects the following SCALANCE X switch products: o SCALANCE X-200: All versions prior to v5.2.3 (only affected by CVE-2018-4848), o SCALANCE X-200 IRT: All versions prior to v5.4.1, and o SCALANCE X300: All versions. 3.2 VULNERABILITY OVERVIEW 3.2.1 IMPROPER NEUTRALIZATION OF INPUT DURING WEB PAGE GENERATION ('CROSS-SITE SCRIPTING') CWE-79 A remote, authenticated attacker with access to the configuration web server could store script code on the website, provided the HRP redundancy option is set. This code could be executed in the web browser of users visiting this website (XSS), affecting its confidentiality, integrity, and availability. User interaction is required for successful exploitation as the user needs to visit the manipulated website. CVE-2018-4842 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L). 3.2.2 IMPROPER NEUTRALIZATION OF INPUT DURING WEB PAGE GENERATION ('CROSS-SITE SCRIPTING') CWE-79 The integrated configuration web server of the affected Scalance X switches could allow XSS attacks if unsuspecting users are tricked into accessing a malicious link. User interaction is required for successful exploitation. The user must be logged into the web interface in order for the exploitation to succeed. CVE-2018-4848 has been assigned to this vulnerability. A CVSS v3 base score of 5.8 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Energy, Food and Agriculture, Healthcare and Public Health, Transportation Systems, and Water and Wastewater Systems o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Marius Rothenbucher and Ali Abbasi reported these vulnerabilities to Siemens Product CERT. 4. MITIGATIONS Siemens has provided updates for the following products to fix the vulnerabilities: o SCALANCE X-200: Update to v5.2.3 https://support.industry.siemens.com/cs/cn/en/view/109758142 o SCALANCE X-200 IRT: Update to v5.4.1 https://support.industry.siemens.com/cs/de/en/view/109758144 As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and following the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity For more information on these vulnerabilities and associated software updates, please see Siemens security advisory SSA-480829 on their website: https://www.siemens.com/cert/advisories 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 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. Additional mitigation guidance and recommended practices are publicly available on the ICS-CERT website 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 NCCIC for tracking and correlation against other incidents. NCCIC also recommends that users take the following measures to protect themselves from social engineering attacks: o Do not click web links or open unsolicited attachments in email messages. o Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. o Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploits specifically target these vulnerabilities. High skill level is needed to exploit. Contact Information For any questions related to this report, please contact the NCCIC at: Email: NCCICCUSTOMERSERVICE@hq.dhs.gov Toll Free: 1-888-282-0870 For industrial control systems cybersecurity information: http://ics-cert.us-cert.gov or incident reporting: https://ics-cert.us-cert.gov/Report-Incident? The NCCIC 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 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 iQIVAwUBWyCP/2aOgq3Tt24GAQi5rQ//c7KHoTsQNmJVfOuZo7Z38U3GALr1/OG+ spWXCLprFXzBhKBk4PON18W4A2HBex9SpOJ5qI16OXw74FEtpOFO6CYYu8bKyraB PYtLuq8JhLQ1411zowNPDFwlqJv4sG+3Ar5Baxfl4/GpzdeEex2bQWJJJNUXouvN Gc+YFX66MFIGHEyhxjADHiv9kv+rp8/PEJvEj2vHHL9s5yXOzr1Zn3t9pcdgBin/ 1KzLFQ2X3Px4U21wCEdd+0mkE48ZCUE3bFEGzh5j3awRdImzx9OU7IBDpWXBXl4L VexM9fGLsuO/rnv7AzxpQFfW4Z1sS3ajKS47COVvk/uVfLr7KEPfvRGqiqEQz5jk Z/wwT0vMotqNN9sDcUDw4okhxYQCVdMIVCnSGvFWRTjalY2YJftklXGsMQ94Tqk9 f6/ArH0ACcMsA5GMsWOXwaR8fEdMval08f8Fx8jlNNMb8sQQhzdvtWKdEzvNYnat vH2mrQ0XVkYXXO6xvgnCGDR7dfNSzpWqSw72wa+ODPl3jpLYbYAOABRw9g4cWNiP bnCaOrS+G97N+nClILxi7qpcdhFFkZ+afZYflaXg1YxQek9pKLqiom7tmR5YaAc0 5bsSNteSbxuDZpCMtdETry1fe6+xpmwX5sQZAusvGrZVQjALcDryTmq/fxhx9FGI 3YHkVn/sMRk= =WvB6 -----END PGP SIGNATURE-----