CVE-2020-5646 in GT1455-QTBDE
Summary
by MITRE • 11/06/2020
NULL pointer dereferences 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 via a specially crafted packet.
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Analysis
by VulDB Data Team • 12/03/2020
This vulnerability represents a critical null pointer dereference flaw within the TCP/IP stack implementation of Mitsubishi Electric's GOT 1000 series touch panel devices, specifically affecting the GT14 model variants. The issue manifests in the firmware versions of these industrial control systems where the network processing functions fail to properly validate incoming packet data before attempting to dereference pointers. The vulnerability exists in the CoreOS operating system versions 05.65.00.BD and earlier across multiple GT1455 and GT1450 series models, making it a widespread concern for industrial environments that rely on these human machine interfaces for operational control. The flaw stems from inadequate input validation mechanisms within the network protocol handling code, where malformed packets can trigger memory access violations that cause the system to crash or become unresponsive.
The technical exploitation of this vulnerability requires an attacker to send a specially crafted network packet to the affected device without authentication, leveraging the inherent weakness in the TCP/IP implementation. When the device receives such a packet, the network processing function attempts to access a null pointer, resulting in a segmentation fault or system crash that halts all network functionality. This type of vulnerability falls under CWE-476 which specifically addresses null pointer dereference conditions, and represents a classic example of improper input validation in network services. The attack vector is particularly dangerous because it requires no authentication credentials and can be executed remotely, making it accessible to any attacker with network access to the affected systems.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise industrial control processes that depend on continuous network connectivity. When the network functions cease to operate, operators lose the ability to communicate with the device, access control interfaces, or monitor system status, which could lead to production downtime and safety risks in manufacturing environments. The vulnerability affects critical infrastructure components where these touch panels serve as primary interfaces for process control and monitoring, meaning that a successful exploitation could result in significant operational disruption. According to ATT&CK framework, this vulnerability maps to T1498 which covers network denial of service attacks, and T1595 which involves network infiltration techniques.
Organizations should immediately implement network segmentation to isolate affected devices from critical operational networks, deploy network monitoring tools to detect unusual packet patterns that might indicate exploitation attempts, and establish emergency response procedures for system recovery. The recommended mitigation involves applying firmware updates from Mitsubishi Electric that address the null pointer dereference issue in the TCP/IP stack implementation, though organizations should verify compatibility with their existing operational systems before deployment. Additionally, implementing network access controls and firewalls to restrict unnecessary network access to these devices can provide additional defense-in-depth layers, while regular vulnerability assessments should be conducted to identify similar weaknesses in other industrial control system components. The vulnerability demonstrates the importance of robust input validation in embedded systems and the need for comprehensive security testing of industrial control firmware before deployment in operational environments.