CVE-2023-41963 in GC-A22W-CW
Summary
by MITRE • 12/12/2023
Denial-of-service (DoS) vulnerability exists in FTP service of HMI GC-A2 series. If a remote unauthenticated attacker sends a specially crafted packets to specific ports, a denial-of-service (DoS) condition may occur.
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Analysis
by VulDB Data Team • 01/02/2024
The vulnerability identified as CVE-2023-41963 represents a critical denial-of-service weakness within the HMI GC-A2 series industrial human-machine interface devices. This flaw specifically targets the File Transfer Protocol service implementation, exposing operational technology infrastructure to remote exploitation by unauthenticated attackers. The affected HMI systems operate in industrial environments where continuous operation is paramount, making such vulnerabilities particularly dangerous as they can disrupt critical manufacturing processes and automation workflows. The vulnerability resides in the protocol handling mechanisms of the FTP service, which fails to properly validate incoming packet structures when processing connections from external sources.
The technical exploitation of this vulnerability occurs through the transmission of specially crafted packets to designated ports within the HMI GC-A2 series devices. These malformed packets trigger an abnormal termination condition within the FTP service daemon, causing the system to become unresponsive and effectively denying service to legitimate users. The flaw demonstrates characteristics consistent with CWE-121, which describes stack-based buffer overflow conditions, or CWE-122, representing heap-based buffer overflow vulnerabilities, where improper input validation leads to service disruption. The attack vector requires only network connectivity to the targeted device ports, making it accessible to remote adversaries without requiring authentication credentials or physical access to the industrial control systems. The vulnerability's impact extends beyond simple service interruption as it can cascade into larger operational failures within the industrial network infrastructure.
From an operational perspective, the implications of CVE-2023-41963 are severe for industrial environments that depend on continuous operation of their HMI systems. The HMI GC-A2 series devices typically serve as critical interfaces between operators and industrial processes, making service disruption potentially catastrophic for production workflows. Attackers can exploit this vulnerability to cause unplanned system outages, leading to production delays, quality control issues, and potential safety hazards in manufacturing environments. The remote nature of the attack means that industrial facilities may be vulnerable to exploitation from anywhere on the internet, without requiring insider knowledge or physical access to the facility. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how industrial control systems remain vulnerable to traditional cyber attacks that target common services like FTP.
Organizations utilizing HMI GC-A2 series devices should implement immediate mitigations including network segmentation to isolate critical industrial systems from general network access, firewall rules to restrict FTP service access to authorized networks only, and regular monitoring for unusual network traffic patterns. The most effective long-term solution involves applying vendor-provided firmware updates that address the specific protocol handling flaws within the FTP service implementation. Network administrators should also consider implementing intrusion detection systems to monitor for suspicious packet patterns that may indicate exploitation attempts. Additionally, implementing network access controls through secure remote access solutions and maintaining detailed network topology documentation helps ensure that any unauthorized access attempts are quickly detected and responded to. The vulnerability underscores the importance of applying security patches promptly and maintaining comprehensive vulnerability management programs for industrial control systems, as these devices often operate in environments where security updates may be delayed due to operational constraints or lack of automated update mechanisms.