Vulnerabilities discovered by researchers in VPN products primarily used for remote access to operational technology (OT) networks can allow hackers to compromise industrial control systems (ICS) and possibly cause physical damage.
Researchers from industrial cybersecurity company Claroty have identified potentially serious vulnerabilities in Secomea GateManager, Moxa EDR-G902 and EDR-G903, and HMS Networks’ eWon. The products are used by many organizations to remotely manage and monitor ICS, including programmable logic controllers (PLCs), input/output devices, and field devices.
Claroty says the impacted VPNs are widely used in the oil and gas and utilities sectors and exploitation could result in attackers gaining access to field devices and potentially causing physical damage.
In Secomea GateManager, which allows users to connect to the internal network from the internet through an encrypted tunnel, researchers discovered multiple security holes, including weaknesses that can be exploited to overwrite arbitrary data (CVE-2020-14500), execute arbitrary code, cause a DoS condition, execute commands as root by connecting via hardcoded Telnet credentials, and obtain user passwords due to weak hashing.
“[CVE-2020-14500] occurs due to improper handling of some of the HTTP request headers provided by the client. This could allow an attacker to remotely exploit GateManager to achieve remote code execution without any authentication required. If carried out successfully, such an attack could result in a complete security breach that grants full access to a customer’s internal network, along with the ability to decrypt all traffic that passes through the VPN,” Claroty explained.
In the Moxa products, researchers discovered a stack-based buffer overflow that can be exploited for remote code execution. This vulnerability, tracked as CVE-2020-14511, was described by Claroty in a blog post earlier this month.
As for the eWON product from HMS Networks, specifically its eCatcher VPN client, Claroty discovered a critical stack-based buffer overflow (CVE-2020-14498) that can be exploited for arbitrary code execution — and ultimately to take complete control of the targeted machine — by getting a user to open a malicious website or email.
Claroty told SecurityWeek that attackers can use search engines such as Shodan and Censys to identify vulnerable instances of the affected remote access servers. Once potential targets have been found, threat actors can exploit the vulnerabilities remotely, without any authentication, to access the devices and eventually the internal VPN network.
The cybersecurity firm says it has mapped instances of GateManager around the world and detected 337 live instances, 253 of which are still vulnerable to CVE-2020-14500. Claroty says it’s still trying to contact some of the companies that were found to be using unpatched versions of GateManager.
The vulnerabilities have been reported by Claroty to their respective vendors, which have released updates that should patch the flaws.
“[Secomea] has released a new version of GateManager 9.2c/9.2i to mitigate the reported vulnerabilities. The most up-to-date release at this time can be found here,” Claroty explained. “Moxa recommends users update EDR-G902/3 to version v5.5 by applying the respective firmware updates available for the EDR-G902 series and EDR-G903 series. Lastly, HMS Networks recommends users update eCatcher to version v6.5.5 or later.”