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Advisory (ICSA-16-175-03)

Meinberg NTP Time Server Vulnerabilities

Original release date: June 23, 2016 | Last revised: August 23, 2018

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Independent researcher Ryan Wincey has identified a stack buffer overflow vulnerability and a privilege escalation vulnerability in Meinberg’s NTP Time Servers Interface. Meinberg has produced a new Version 6.20.004 to mitigate these vulnerabilities. The researcher has validated the firmware update. He confirms the update fixes these vulnerabilities.

These vulnerabilities could be exploited remotely.


The following Meinberg products are affected:

  • IMS-LANTIME M3000 Version 6.0 and earlier,
  • IMS-LANTIME M1000 Version 6.0 and earlier,
  • IMS-LANTIME M500 Version 6.0 and earlier,
  • LANTIME M900 Version 6.0 and earlier,
  • LANTIME M600 Version 6.0 and earlier,
  • LANTIME M400 Version 6.0 and earlier,
  • LANTIME M300 Version 6.0 and earlier,
  • LANTIME M200 Version 6.0 and earlier,
  • LANTIME M100 Version 6.0 and earlier,
  • SyncFire 1100 Version 6.0 and earlier, and
  • LCES Version 6.0 and earlier.


Successful exploitation of these vulnerabilities could cause a buffer overflow condition that may allow escalation to root privileges.

Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation.


Meinberg is a Germany-based company that maintains offices around the world, including North America, South America, Europe, Asia, Africa, and Australia.

The affected products are NTP Time Servers. According to Meinberg, IMS-LANTIME, LANTIME, SyncFire, and LCES Series are deployed across several sectors including Communications, Defense Industrial Base, Energy, Financial Services, Transportation Systems, and others. Meinberg estimates that these products are used worldwide.




Remote stack buffer overflow vulnerability involving parsing of parameter in POST request in function provides privilege of web server “nobody.”

CVE-2016-3962b has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).c


Remote stack buffer overflow vulnerability is present while parsing nine different parameters in POST request in function.

CVE-2016-3988e has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/ C:L/I:L/A:L).f


Weak access controls allow for privilege escalation from “nobody” to “root” user. “nobody” has permissions to alter script that can only run as “root.”

CVE-2016-3989h has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).i



These vulnerabilities could be exploited remotely.


No known public exploits specifically target these vulnerabilities.


An attacker with a low skill would be able to exploit these vulnerabilities.


Meinberg has produced a new firmware Version 6.20.004. The new firmware can be downloaded by using the link below:


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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