CVE-2024-50696 in WiNet-S
Summary
by MITRE • 02/26/2025
SunGrow WiNet-S V200.001.00.P025 and earlier versions is missing integrity checks for firmware upgrades. Sending a specific MQTT message allows an update to an inverter or a WiNet connectivity dongle with a bogus firmware file that is located on attacker-controlled server.
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Analysis
by VulDB Data Team • 06/01/2025
The vulnerability identified as CVE-2024-50696 affects SunGrow WiNet-S devices running firmware versions V200.001.00.P025 and earlier, representing a critical security flaw in the device firmware update mechanism. This issue stems from the complete absence of integrity verification checks during the firmware upgrade process, creating a pathway for malicious actors to compromise connected solar inverters and WiNet connectivity dongles through unauthorized firmware installations. The vulnerability specifically leverages the MQTT protocol as an attack vector, allowing remote exploitation without requiring physical access to the devices.
The technical flaw resides in the firmware update implementation where the device fails to validate the authenticity and integrity of firmware images received through MQTT messages. This missing validation mechanism enables attackers to craft malicious MQTT messages containing references to attacker-controlled servers hosting manipulated firmware files. The device automatically downloads and installs these firmware updates without performing cryptographic checksums, digital signatures, or other integrity verification mechanisms that should normally protect against tampered firmware components. This weakness aligns with CWE-353, which addresses the lack of integrity checks in software update mechanisms, and represents a fundamental failure in secure update protocols.
The operational impact of this vulnerability is severe as it allows remote code execution and complete compromise of affected devices. An attacker with network access to the MQTT communication channel can replace legitimate firmware with malicious code, potentially leading to device malfunction, complete system compromise, or enabling further attacks on the broader solar energy infrastructure. The vulnerability affects critical components of the solar energy monitoring and control system, where inverters and connectivity dongles serve as essential nodes in the distributed energy network. This represents a significant risk to both residential and commercial solar installations, as compromised devices could lead to operational failures, safety hazards, or unauthorized access to energy consumption data.
Mitigation strategies should include immediate firmware updates from SunGrow to address the missing integrity checks, network segmentation to isolate affected devices from critical systems, and monitoring of MQTT traffic for suspicious firmware update requests. Organizations should implement network access controls to restrict MQTT communication to trusted sources only, deploy intrusion detection systems to monitor for unauthorized firmware update activities, and establish secure firmware distribution channels with proper digital signatures. The vulnerability demonstrates the importance of implementing proper update integrity verification as outlined in the NIST Cybersecurity Framework and aligns with ATT&CK technique T1072 for software deployment tools and T1547.001 for registry run keys. Additionally, this vulnerability underscores the critical need for secure boot mechanisms and proper firmware validation processes in IoT devices, particularly those operating in critical infrastructure environments where reliability and security are paramount to system operation.