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AUSCERT External Security Bulletin Redistribution
Advisory (icsa-19-260-02) Siemens SINEMA Remote Connect Server
20 September 2019
AusCERT Security Bulletin Summary
Product: Siemens SINEMA Remote Connect Server
Operating System: Network Appliance
Impact/Access: Access Privileged Data -- Remote with User Interaction
Cross-site Request Forgery -- Remote with User Interaction
CVE Names: CVE-2019-34623 CVE-2019-13922 CVE-2019-13920
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ICS Advisory (ICSA-19-260-02)
Siemens SINEMA Remote Connect Server
Original release date: September 17, 2019
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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/
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/
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
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/
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
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/
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
Hendrik Derre and Tijl Deneut from HOWEST reported these vulnerabilities to
Siemens recommends users upgrade to Versions 2.0 SP1 or later for the affected
The v2.0 SP1 update can be obtained at the following location:
For more information on these vulnerabilities and associated software updates,
please see Siemens' security advisory SSA-884497 at: https://www.siemens.com/
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
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
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.
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