CVE-2017-16303 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_ex, at 0x9d01addc, the value for the `cmd2` key is copied using `strcpy` to the buffer at `$sp+0x280`.This buffer is 16 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 01/12/2023
The vulnerability described in CVE-2017-16303 represents a critical stack-based buffer overflow affecting the Insteon Hub device firmware version 1012. This flaw exists within the PubNub message handler specifically targeting the "cc" channel, creating a significant security risk for connected home automation systems. The vulnerability stems from improper input validation and unsafe string handling practices that allow attackers to manipulate memory structures through crafted malicious payloads. The affected device operates as a central hub for Insteon smart home devices, making this vulnerability particularly concerning for residential and commercial automation environments.
The technical implementation of this vulnerability occurs within the cmd sn_ex function at memory address 0x9d01addc where the system processes the `cmd2` key value through an unsafe `strcpy` operation. This function copies data from the PubNub service into a buffer located at `$sp+0x280` which has a fixed size of only 16 bytes. When an attacker sends a malicious payload exceeding this buffer capacity, the overflow propagates into adjacent memory locations, potentially overwriting critical program data, return addresses, or other stack variables. The use of `strcpy` instead of safer alternatives like `strncpy` or `snprintf` directly violates secure coding practices and creates predictable memory corruption patterns that can be exploited for arbitrary code execution. This vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides potential attackers with pathways for remote code execution and system compromise. An attacker capable of sending authenticated HTTP requests to the vulnerable device can leverage this flaw to gain unauthorized control over the Insteon Hub, potentially accessing or modifying configuration data, controlling connected smart home devices, or using the compromised device as a pivot point for attacking other systems within the network. The authentication requirement for triggering this vulnerability does not eliminate the risk, as it suggests that attackers who have gained access to legitimate credentials or can exploit other authentication bypass mechanisms can directly target this vulnerability. This weakness creates a persistent threat vector that can be exploited repeatedly, particularly in environments where the device remains connected to the internet or where network segmentation is inadequate.
Mitigation strategies for this vulnerability should encompass both immediate defensive measures and long-term architectural improvements. Organizations should prioritize firmware updates from Insteon to address the identified buffer overflow issue, as the manufacturer likely released patches to correct the unsafe string handling practices. Network segmentation should be implemented to limit access to the Insteon Hub device, ensuring that only authorized systems can communicate with it through the PubNub service. Additional protective measures include implementing strict input validation and sanitization for all external communications, replacing vulnerable `strcpy` calls with secure alternatives, and monitoring network traffic for suspicious patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of following secure coding guidelines and adheres to ATT&CK technique T1059.007 for Command and Scripting Interpreter, where adversaries may exploit buffer overflows to execute malicious commands through compromised systems. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other networked devices within the smart home ecosystem.