CVE-2022-0367 in libmodbus
Summary
by MITRE • 08/29/2022
A heap-based buffer overflow flaw was found in libmodbus in function modbus_reply() in src/modbus.c.
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Analysis
by VulDB Data Team • 11/05/2025
The heap-based buffer overflow vulnerability identified as CVE-2022-0367 resides within the libmodbus library, specifically affecting the modbus_reply() function located in the src/modbus.c source file. This flaw represents a critical security weakness that can be exploited to compromise systems relying on modbus communication protocols. The vulnerability manifests when the library processes malformed or excessively large data packets, causing memory corruption that can lead to arbitrary code execution or system instability. Given that libmodbus is widely deployed in industrial control systems, building automation, and energy management platforms, the potential impact extends across critical infrastructure sectors where modbus protocol communication is prevalent.
The technical implementation of this buffer overflow stems from inadequate input validation within the modbus_reply() function, which fails to properly bounds-check data being written to heap-allocated memory regions. When processing modbus requests containing oversized data payloads or malformed packet structures, the function attempts to write data beyond the allocated buffer boundaries, resulting in heap corruption. This memory corruption can overwrite adjacent memory locations, potentially corrupting program state, function pointers, or return addresses. The vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a classic example of insufficient boundary checking in memory management operations. The flaw is particularly concerning because it operates within the core communication handling code of the library, making it accessible through normal modbus protocol interactions.
The operational impact of CVE-2022-0367 extends beyond simple system crashes or denial of service conditions, as it enables remote code execution capabilities that can be leveraged by attackers to gain unauthorized access to industrial control systems. Systems utilizing libmodbus for communication between programmable logic controllers, sensors, and monitoring devices become vulnerable to exploitation, potentially allowing attackers to manipulate industrial processes, disrupt operations, or gain persistent access to critical infrastructure environments. The vulnerability affects numerous industrial protocols and applications that depend on libmodbus, including but not limited to energy management systems, water treatment facilities, manufacturing automation, and power grid monitoring solutions. This exposure creates significant risk for organizations operating within the attack surface defined by MITRE ATT&CK framework's TA0002 (Execution) and TA0003 (Persistence) tactics, as successful exploitation could lead to both immediate system compromise and long-term access to critical infrastructure.
Mitigation strategies for CVE-2022-0367 should prioritize immediate patching of affected libmodbus versions, with security updates typically addressing the buffer overflow through proper input validation and bounds checking mechanisms. Organizations should implement network segmentation to limit modbus protocol exposure and deploy intrusion detection systems to monitor for anomalous modbus traffic patterns that could indicate exploitation attempts. Additionally, implementing robust input sanitization at network boundaries and conducting regular security assessments of industrial control systems can help reduce the attack surface. The vulnerability highlights the importance of applying security patches promptly in industrial environments, as delays in remediation can leave critical infrastructure exposed to sophisticated attacks that may exploit similar memory corruption vulnerabilities within operational technology environments.