ICS Advisory

Siemens SINEMA Remote Connect Server Cross-site Scripting Vulnerability

Last Revised
Alert Code
ICSA-16-208-03

OVERVIEW

Researchers Antonio Morales Maldonado of INNOTEC SYSTEM, and Alexander Van Maele and Tijl Deneut of Howest have identified a cross-site scripting (XSS) vulnerability in the Siemens SINEMA Remote Connect Server application. Siemens has produced an update to mitigate this vulnerability.

This vulnerability could be exploited remotely.

AFFECTED PRODUCTS

The following SINEMA Remote Connect Server versions are affected:

  • SINEMA Remote Connect Server, all versions prior to Version 1.2

IMPACT

Exploiting this vulnerability could enable attackers to read some files from Siemens SINEMA Remote Connect Server devices. This could enable a remote attacker ongoing access to these devices.

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

Siemens is a multinational company headquartered in Munich, Germany.

The affected product, SINEMA Remote Connect Server, is a network management appliance for industrial applications and allows network monitoring as well as diagnostics and reporting functions integrated into SCADA systems such as WinCC. According to Siemens, SINEMA products are deployed across several sectors including Chemical, Commercial Facilities, Critical Manufacturing, Energy, Government Facilities, Water and Wastewater Systems, and others. Siemens estimates that this product is used primarily in the United States and Europe with a small percentage in Asia.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

CROSS-SITE SCRIPTINGCWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), http://cwe.mitre.org/data/definitions/79.html, web site last accessed July 26, 2016.

The integrated web server (Port 443/TCP) of the affected SINEMA Remote Connect Server could allow XSS attacks if unsuspecting users are tricked into accessing a malicious link.

CVE-2016-6204NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-6204, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. has been assigned to this vulnerability. A CVSS v3 base score of 4.7 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N).CVSS Calculator https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N/E:P/RL:O/RC:C, web site last accessed July 26, 2016.

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. Social engineering is required to convince the user into accessing a malicious link. This decreases the likelihood of a successful exploit.

MITIGATION

Siemens provides software update V1.2 for SINEMA Remote Connect Server which fixes the vulnerability and recommends users update to the new version. The software update for SINEMA Remote Connect Server can be obtained at:

https://support.industry.siemens.com/cs/ww/en/view/109737963

As a general security measure, Siemens strongly recommends to configure the environment according to its operational guidelines available at:

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-119132 at the following location:

http://www.siemens.com/cert/en/cert-security-advisories.htm

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.
  • Locate control system networks and remote devices behind firewalls, and isolate them from the business network.

In addition, ICS-CERT recommends that users take the following measures to protect themselves from social engineering attacks:

  • Do not click web links or open unsolicited attachments in email messages.
  • Refer to Recognizing and Avoiding Email ScamsRecognizing and Avoiding Email Scams, http://www.us-cert.gov/reading_room/emailscams_0905.pdf, web site last accessed July 26, 2016. for more information on avoiding email scams.
  • Refer to Avoiding Social Engineering and Phishing AttacksNational Cyber Alert System Cyber Security Tip ST04-014, http://www.us-cert.gov/cas/tips/ST04-014.html, web site last accessed July 26, 2016. for more information on social engineering attacks.

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 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 (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.

This product is provided subject to this Notification and this Privacy & Use policy.

Vendor

Siemens