CVE-2020-5644 in GT1455-QTBDE
Summary
by MITRE • 11/06/2020
Buffer overflow vulnerability in TCP/IP function included in the firmware of GT14 Model of GOT 1000 series (GT1455-QTBDE CoreOS version "05.65.00.BD" and earlier, GT1450-QMBDE CoreOS version "05.65.00.BD" and earlier, GT1450-QLBDE CoreOS version "05.65.00.BD" and earlier, GT1455HS-QTBDE CoreOS version "05.65.00.BD" and earlier, and GT1450HS-QMBDE CoreOS version "05.65.00.BD" and earlier) allows a remote unauthenticated attacker to stop the network functions of the products or execute a malicious program via a specially crafted packet.
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Analysis
by VulDB Data Team • 12/03/2020
This buffer overflow vulnerability exists within the TCP/IP stack implementation of Mitsubishi Electric's GOT 1000 series HMI devices, specifically affecting the GT14 model line with CoreOS versions 05.65.00.BD and earlier. The flaw resides in the network protocol handling functions that process incoming packets without proper bounds checking, creating a condition where maliciously crafted network traffic can exceed allocated memory buffers. The vulnerability is classified as a classic buffer overflow (cwe-121) that occurs when the system attempts to write data beyond the allocated buffer boundaries in memory. This particular implementation affects multiple variants within the GT14 series including GT1455-QTBDE, GT1450-QMBDE, GT1450-QLBDE, GT1455HS-QTBDE, and GT1450HS-QMBDE models, all sharing the same vulnerable firmware components. The attack vector is particularly concerning as it requires no authentication and can be executed remotely, making it highly accessible to threat actors.
The technical exploitation of this vulnerability allows an attacker to manipulate the network stack functions through specially crafted network packets that trigger the buffer overflow condition. When the malformed packet is received, the system's TCP/IP processing function fails to validate the packet size against the allocated buffer space, causing memory corruption that can lead to two primary outcomes. The first outcome involves a denial of service condition where the network functions of the device become unavailable, effectively rendering the HMI system inoperable for its intended purpose. The second, more severe outcome, enables remote code execution capabilities where attackers can inject and execute arbitrary malicious code within the device's operating environment. This dual nature of impact makes the vulnerability particularly dangerous in industrial control systems where continuous operation is critical for process control and safety mechanisms.
From an operational security perspective, this vulnerability presents significant risks to industrial environments that rely on Mitsubishi GOT 1000 series HMI systems for critical operations. The remote unauthenticated nature of the attack means that adversaries can exploit the vulnerability from outside the network perimeter without requiring legitimate credentials or physical access to the devices. This characteristic aligns with attack patterns described in the mitre att&ck framework under the initial access and execution phases, where attackers leverage network-based vulnerabilities to establish footholds within industrial control systems. The affected devices operate in environments where network availability is paramount, and the potential for service disruption can lead to production halts, safety system failures, or process control malfunctions that could result in significant financial losses or operational safety concerns.
Mitigation strategies for this vulnerability should include immediate firmware updates from Mitsubishi Electric to address the buffer overflow condition in the TCP/IP stack implementation. Organizations should also implement network segmentation and access controls to limit exposure of these devices to untrusted network zones, utilizing firewalls and network access control lists to restrict incoming traffic to only necessary protocols and ports. Additional defensive measures include monitoring network traffic for anomalous packet patterns that might indicate exploitation attempts, implementing intrusion detection systems specifically configured to detect malformed TCP/IP packets targeting industrial control systems, and establishing network monitoring procedures to detect service disruptions or unusual behavior that could indicate successful exploitation of the vulnerability. The remediation process must also include thorough testing of updated firmware in controlled environments before deployment to ensure that the patches do not introduce compatibility issues with existing industrial processes or control system configurations.