WellinTech KingView History Server Buffer Overflow
ICSA： ICS Advisory (ICSA-11-355-02)
ICS-CERT has received a report from the Zero Day Initiative (ZDI) concerning a heap-based buffer overflow vulnerability in WellinTech’s Kingview HistoryServer.exe, which may allow a remote, unauthenticated attacker to execute arbitrary code. This vulnerability was reported to ZDI by independent security researcher Luigi Auriemma.
WellinTech has produced a patch that is available for download from its website.
The following WellinTech KingView version is affected:
- KingView V65.30.2010.18018
Successful exploitation of the heap overflow vulnerability could allow a remote attacker to cause the service to crash, and also may allow the execution of arbitrary code.
Impact to individual organizations depends on many factors that are unique to each organization. ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.
WellinTech is a software development company specializing in the Automation and Control industry based in Beijing, China. According to WellinTech, they also have branches in United States, Japan, Singapore, Europe, and Taiwan.
According to the WellinTech, KingView is a Windows-based control, monitoring and data collection application used across several sectors including power, water, building automation, mining, and other sectors.
An attacker can exploit this vulnerability by sending a specially crafted packet to Port 777/TCP that exceeds a specified length and contains executable code.
CVE-2011-4536 has been assigned to this vulnerability. A CVSS V2 base score of 10 has also been assigned.
This vulnerability is remotely exploitable.
Existence of Exploit
No known exploits specifically target this vulnerability.
An attacker would require an intermediate skill level to exploit this vulnerability.
WellinTech has created a patch and instructions for installation that is available for download on its website at:
- English: http://en.wellintech.com/news/detail.aspx?contentid=166
- Chinese: http://www.kingview.com/news/detail.aspx?contentid=587
ICS-CERT encourages asset owners to take additional defensive measures to protect against this and other cybersecurity risks.
- Implement network or host-based firewall rules to limit network access to Port 777/TCP.
- Minimize network exposure for all control system devices. Critical devices should not directly face 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 VPN is only as secure as the connected devices.
The Control Systems Security Program (CSSP) also provides a section for control system security recommended practices on the CSSP web page. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.
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. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.
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 e-mail messages.
- Refer to Recognizing and Avoiding Email Scams for more information on avoiding e-mail scams.
- Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.