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Advisory (ICSA-15-288-01)

3S CODESYS Runtime Toolkit Null Pointer Dereference Vulnerability

Original release date: October 15, 2015

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Nicholas Miles of Tenable Network Security has identified a NULL pointer dereference vulnerability in 3S-Smart Software Solutions GmbH’s CODESYS Runtime Toolkit. 3S has produced a new version to mitigate this vulnerability.

This vulnerability could be exploited remotely.


The following CODESYS software versions are affected:

  • CODESYS Runtime Toolkit, versions prior to Version


Successful exploitation of this vulnerability may allow a remote attacker to crash the Runtime Toolkit, resulting in a denial of service condition.

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.


3S-Smart Software Solutions GmbH is headquartered in Kempten, Germany, and has distributors in more than 10 countries worldwide.

The affected product, CODESYS Runtime Toolkit, is embedded third-party software. According to 3S, CODESYS is deployed across several sectors including Critical Manufacturing, Energy, Transportation Systems, and others. 3S-Smart Software Solutions GmbH estimates that these products are used worldwide.




A crafted request may allow a NULL pointer dereference that could crash the Runtime Toolkit causing a denial-of-service condition.

CVE-2015-6482b has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).c



This vulnerability could be exploited remotely.


No known public exploits specifically target this vulnerability.


An attacker with a low skill would be able to exploit this vulnerability.


3S-Smart Software Solutions GmbH has released a new version of CODESYS, Version, which contains a new version of the Runtime Toolkit, Version CODESYS, Version is available at the following location with a valid user account:


For additional information about the new version of CODESYS or questions about the vulnerability, the CODESYS Support Team’s contact information is as follows:


ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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 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.

Contact Information

For any questions related to this report, please contact the NCCIC at:

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?

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