Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.3248 Download of Code without Integrity Check in Siemens LOGO! Soft Comfort 20 December 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: LOGO! Soft Comfort Publisher: Siemens Operating System: Network Appliance Impact/Access: Reduced Security -- Remote/Unauthenticated Resolution: Mitigation CVE Names: CVE-2017-12740 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-17-353-04 - --------------------------BEGIN INCLUDED TEXT-------------------- ATTENTION: Remotely exploitable. Vendor: Siemens Equipment: LOGO! Soft Comfort Vulnerability: Download of Code without Integrity Check AFFECTED PRODUCTS Siemens reports that the vulnerability affects the following LOGO! Soft Comfort engineering software products: * LOGO! Soft Comfort: All versions prior to V8.2 IMPACT Successful exploitation of this vulnerability could allow a remote attacker in a privileged network position to manipulate a software package during download. MITIGATION Siemens removed the Update Center from LOGO! Soft Comfort V8.2 and provides SHA-256 checksums for all LOGO! Soft Comfort software packages via a secured HTTPS channel. Siemens recommends verifying legitimacy by comparing the SHA-256 checksum of the downloaded software package with the SHA-256 checksum provided for the software package. Software version 8.2 for LOGO! Soft Comfort and SHA-256 checksums for LOGO! Soft Comfort downloads can be obtained via: https://www.siemens.com/logo-update As a general security measure, Siemens strongly recommends protecting network access to the devices with appropriate mechanisms. Siemens advises configuring the environment according to Siemens operational guidelines in order to run the devices in a protected IT environment. https://www.siemens.com/cert/operational-guidelines-industrial-security For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-888929 at the following location: http://www.siemens.com/cert/en/cert-security-advisories.htm NCCIC/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. 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 ICS?CERT 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. 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. In addition, ICS-CERT recommends that users take the following measures to protect themselves from social engineering attacks: 1. Do not click web links or open unsolicited attachments in email messages. 2. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. 3. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploits specifically target this vulnerability. High skill level is needed to exploit. VULNERABILITY OVERVIEW DOWNLOAD OF CODE WITHOUT INTEGRITY CHECK CWE-494 The update center of LOGO! Soft Comfort lacks integrity verification on software packages downloaded via an unprotected communication channel. This could allow a remote attacker to manipulate the software package while performing a man-in-the-middle (MitM) attack. CVE-2017-12740 has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:N /I:H/A:N). RESEARCHER Tobias Gebhardt reported this vulnerability to Siemens. BACKGROUND Critical Infrastructure Sectors: Commercial Facilities, Transportation Systems Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany 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? - --------------------------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 iQIVAwUBWjoNTox+lLeg9Ub1AQiFzQ//YdHD2HaFIW2j0qOZDWvummxq7DvRkkff uvxjsWuo5T1uc+7q69+KRzY3zuKkbC25ULH0isa5ERpETcRqARQGYI1za8ENjPw+ j2ICdhNByR2GjO8VVEiCVrLXgO0bJv+mYRmk6gpzVePQz+yIkJHfMBHLpoYAENHj oU13QGi9jadHr81mEH13Udk9dynBLYf/RmSL7j5rwm0CgFhsjwEy21t7zk+RifrI 0IoSG8E3MbXDicJYaPKDQ41yyDsP4mez04cXZHC4jHGOjB4hB8hkcqq87/lu/5Ep 4ggcKPx3uI5rolapTQmqCZ+U5HHcLwIxS4/yL1GAaq8hjA6SfqMkV8/efoI2RLtb LibUb5+nyUAhB2JUBNXJt8cFpX5KngFohwF13IWRB2LFs2jtvGzGUoIQy26A0Dv2 zOzbL6/r0ZDY19xKR+gOm0m7LlC5ancDF89/RYv92VQLxBcMQ8rl4z0+qMKnPymd hdJzTxvnl+jS9allC1rd2oPgH+kepRczmbpel4QVP4DaCJ03Novx3j9FvXPowYrA 2MX67ruIxHbiy9eW72FhHQiPoOKKqiMffskRfB0Agu3LX9MC2HrIy7QSFSNvOpEX c6PvGausJ3b9XS1sPle1QNsyAk70ycv0n/WxpjMdfe9pLBunyNxKLh1PKvVgTbqF ZVJRrozGH3Q= =qhyW -----END PGP SIGNATURE-----