CVE-2018-18601 in GZ621W
Summary
by MITRE
The TK_set_deviceModel_req_handle function in the cloud communication component in Guardzilla GZ621W devices with firmware 0.5.1.4 has a Buffer Overflow.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2018-18601 represents a critical buffer overflow flaw within the Guardzilla GZ621W security device firmware version 0.5.1.4. This issue resides in the TK_set_deviceModel_req_handle function which processes cloud communication requests, making it a significant concern for IoT device security. The vulnerability stems from inadequate input validation and memory management practices within the device's communication stack, creating an exploitable condition that could allow remote attackers to compromise the device's operational integrity.
The technical implementation of this buffer overflow occurs when the TK_set_deviceModel_req_handle function processes incoming device model requests from cloud services without proper bounds checking on the input data. This function fails to validate the length of incoming data before copying it into fixed-size buffers, creating a classic stack-based buffer overflow condition. The vulnerability manifests when an attacker sends a maliciously crafted request containing excessive data that exceeds the allocated buffer space, potentially overwriting adjacent memory locations including return addresses and function pointers. This flaw directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-787, which addresses out-of-bounds write vulnerabilities.
The operational impact of this vulnerability extends beyond simple device compromise, as it provides attackers with potential pathways for privilege escalation and persistent access to the Guardzilla GZ621W device. Remote exploitation could enable attackers to execute arbitrary code on the device, potentially leading to complete system takeover, data exfiltration, or use of the device as a pivot point for attacking other networked systems. The cloud communication component's exposure to external network connections makes this vulnerability particularly dangerous, as it allows attackers to exploit the flaw without physical access to the device. This scenario aligns with ATT&CK technique T1059.007 for command and control through cloud services, and T1068 for privilege escalation through buffer overflow exploitation.
Mitigation strategies for CVE-2018-18601 should focus on immediate firmware updates from the vendor, which would address the underlying buffer overflow condition through proper input validation and memory management. Network segmentation and access controls should be implemented to limit exposure of the device to untrusted networks, while monitoring systems should be deployed to detect anomalous communication patterns that might indicate exploitation attempts. Additionally, implementing network-based intrusion detection systems can help identify and block malicious requests targeting this specific vulnerability. Organizations should also consider disabling unnecessary cloud communication features when not required, reducing the attack surface available to potential exploiters. The vulnerability highlights the importance of secure coding practices in IoT device development, particularly around memory management and input validation, and serves as a reminder of the critical need for regular security assessments of embedded systems.