CVE-2017-16308 in Insteon
Summary
by MITRE • 01/12/2023
Multiple exploitable buffer overflow vulnerabilities exist in the PubNub message handler for the "cc" channel of Insteon Hub running firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriting arbitrary data. An attacker should send an authenticated HTTP request to trigger this vulnerability. In cmd sn_exw, at 0x9d01b374, the value for the `cmd2` key is copied using `strcpy` to the buffer at `$sp+0x2b0`.This buffer is 32 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/04/2023
The vulnerability described in CVE-2017-16308 represents a critical stack-based buffer overflow within the Insteon Hub's PubNub message handling functionality, specifically targeting the "cc" channel. This flaw exists in firmware version 1012 of the Insteon Hub device, which operates as a smart home automation hub connecting various IoT devices through a centralized control system. The vulnerability stems from improper input validation within the command processing mechanism that handles messages transmitted through the PubNub messaging service, creating an exploitable condition that could allow remote code execution or system compromise. The affected component resides in the sn_exw command handler where the device processes incoming commands from the PubNub service, making it a potential entry point for attackers targeting home automation networks.
The technical implementation of this vulnerability demonstrates a classic buffer overflow scenario where the application uses the unsafe strcpy function to copy data from the cmd2 key parameter into a stack buffer that is only 32 bytes in size. The buffer is located at stack pointer offset $sp+0x2b0, and when an attacker sends a payload exceeding 32 bytes, the excess data overflows into adjacent stack memory locations, potentially overwriting return addresses, saved registers, and other critical program state information. This particular implementation violates the principle of safe string handling and directly maps to CWE-121, which describes stack-based buffer overflow conditions, while also aligning with CWE-787, which covers out-of-bounds write vulnerabilities. The use of strcpy without bounds checking creates an exploitable condition that can be leveraged to manipulate program execution flow, particularly since the vulnerability occurs during the processing of authenticated HTTP requests, reducing the attack surface complexity.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides potential attackers with the capability to execute arbitrary code on the affected Insteon Hub device. This represents a significant security risk for home automation networks, as the compromised device could serve as a foothold for further lateral movement within the network, potentially allowing attackers to access other connected IoT devices or even gain access to network resources beyond the immediate device. The vulnerability's exploitation requires an authenticated HTTP request, which means that an attacker would need to obtain valid credentials or exploit another vulnerability to gain access to the device's management interface. However, once exploited, the buffer overflow could enable complete system compromise, allowing attackers to install malicious software, modify device configuration, or use the device as a pivot point for attacks against other networked systems. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security improvements within the Insteon Hub ecosystem. The most direct solution involves patching the firmware to either replace the unsafe strcpy usage with a safe alternative such as strncpy or strlcpy, or by implementing proper input validation that bounds the length of data copied to the buffer. Network-level protections should include implementing strict access controls for the device's HTTP management interface, requiring strong authentication mechanisms, and monitoring for suspicious activity patterns that might indicate exploitation attempts. Organizations should also consider network segmentation to limit the potential impact of compromise, ensuring that IoT devices are isolated from critical network resources. Additionally, regular firmware updates and security audits should be implemented to identify and address similar vulnerabilities in other components of the smart home ecosystem. The vulnerability highlights the importance of secure coding practices, particularly the avoidance of dangerous functions like strcpy in favor of safer alternatives, and demonstrates how seemingly minor coding oversights can create significant security risks in IoT environments where devices often lack robust security monitoring capabilities.