CVE-2017-16261 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 g_b, at 0x9d015714, the value for the `grp` key is copied using `strcpy` to the buffer at `$sp+0x280`.This buffer is 16 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/05/2023
The vulnerability identified as CVE-2017-16261 represents a critical stack-based buffer overflow flaw within the Insteon Hub's PubNub message handling mechanism. This security weakness specifically targets the "cc" channel functionality of the device's firmware version 1012, creating a pathway for remote exploitation that could compromise the entire home automation system. The flaw resides in how the device processes incoming messages through the PubNub messaging service, which serves as a communication bridge between the hub and external control systems. The vulnerability's exploitation requires an authenticated HTTP request, indicating that while it may not be entirely publicly exploitable, it presents a significant risk to systems where unauthorized access to the hub's administrative interface or associated services has occurred.
The technical implementation of this buffer overflow occurs within the cmd g_b function at memory address 0x9d015714, where the system processes the `grp` key value from incoming messages. The vulnerable code utilizes the unsafe `strcpy` function to copy data from the received PubNub message into a buffer located at `$sp+0x280` on the stack. This buffer has a fixed size of only 16 bytes, creating an immediate and predictable overflow condition when the incoming data exceeds this limit. The use of `strcpy` without proper bounds checking represents a classic CWE-121 buffer overflow vulnerability, where the copying operation continues until it encounters a null terminator, regardless of the destination buffer capacity. This fundamental flaw allows an attacker to overwrite adjacent stack memory locations, potentially including return addresses, saved registers, and other critical program state information.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides attackers with the capability to execute arbitrary code on the Insteon Hub device. When an attacker successfully exploits this buffer overflow, they can manipulate the program's execution flow by overwriting the return address on the stack, potentially redirecting execution to malicious code injected into the buffer or other memory locations. This type of vulnerability falls under the ATT&CK framework's technique T1059 for command and script injection, and T1068 for exploit for privilege escalation, as the compromised device controls home automation functions and could provide access to other connected IoT devices within the network. The Insteon Hub's role as a central communication hub for home automation systems means that successful exploitation could lead to complete compromise of the home network's security infrastructure.
Mitigation strategies for this vulnerability should focus on immediate firmware updates provided by Insteon to address the buffer overflow in the PubNub message handler. Network segmentation and access control measures should be implemented to limit direct access to the hub's administrative interfaces and PubNub communication channels. The use of intrusion detection systems that monitor for unusual PubNub message patterns and command sequences can help detect potential exploitation attempts. Additionally, implementing proper input validation and bounds checking in the application code, replacing `strcpy` with safer alternatives such as `strncpy` or `strlcpy`, would prevent the buffer overflow condition from occurring. Organizations should also consider network monitoring solutions that can detect and alert on anomalous communication patterns that may indicate exploitation attempts, as this vulnerability represents a significant risk to home automation security and could potentially be leveraged for broader network infiltration. The vulnerability demonstrates the importance of secure coding practices in IoT devices and the critical need for regular security assessments of embedded systems.