Code Execution Flaws Found in WECON Industrial Products

A significant number of vulnerabilities have been found recently in products from China-based WECON, but the vendor has been slow to release patches.

WECON specializes in human-machine interfaces (HMIs), programmable logic controllers (PLCs), and industrial PCs. The company’s products are used all around the world, particularly in the critical manufacturing, energy, and water and wastewater sectors.

An advisory published recently by ICS-CERT reveals that researchers Mat Powell and Natnael Samson discovered several vulnerabilities in WECON’s PI Studio HMI software. The list includes a critical stack-based buffer overflow that allows remote code execution, a high severity out-of-bounds write bug that also allows code execution, and two medium severity information disclosure flaws.

According to ICS-CERT, WECON has confirmed the vulnerabilities, but it has yet to release any patches.

ICS-CERT has this year published four advisories describing vulnerabilities in WECON products, including a medium severity flaw in the company’s PLC Editor ladder logic software, and several high and medium severity bugs in LeviStudio applications.

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All the vulnerabilities for which ICS-CERT has published advisories were reported by Samson, Powell and other researchers through Trend Micro’s Zero Day Initiative (ZDI).

In fact, ZDI has already published 116 advisories in 2018 and over a dozen will be published in the upcoming period. However, it’s worth noting that ZDI typically publishes multiple advisories for a single CVE as each advisory covers a variation of the same vulnerability.

On the other hand, many of the ICS-CERT advisories and a vast majority of the advisories from ZDI were published before patches were made available by the vendor.

A majority of the security holes allow remote code execution, but since they are related to how the affected applications handle certain file types, the attacker would need to convince the targeted user to open a specially crafted file in order to trigger the exploit.

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