CVE-2017-16266 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 s_b, at 0x9d016530, the value for the `grp` key is copied using `strcpy` to the buffer at `$sp+0x1b4`.This buffer is 8 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/04/2023
The CVE-2017-16266 vulnerability represents a critical stack-based buffer overflow flaw within the Insteon Hub's PubNub message handling system, specifically targeting the "cc" channel functionality. This vulnerability exists in firmware version 1012 of the Insteon Hub device, which operates as a smart home automation hub that communicates with various IoT devices through the PubNub messaging service. The flaw stems from improper input validation and unsafe string handling mechanisms within the device's firmware, creating a pathway for remote code execution and system compromise. The vulnerability is particularly concerning as it leverages the PubNub service, which is commonly used for real-time communication in IoT ecosystems, making it accessible to attackers who can craft malicious payloads through this communication channel.
The technical implementation of this vulnerability occurs within the cmd s_b function at memory address 0x9d016530 where the system processes incoming data from the PubNub service. The specific flaw manifests when the system copies data from the `grp` key parameter into a buffer located at stack offset $sp+0x1b4. This buffer has a fixed size of only 8 bytes, while the input data can be arbitrarily long, creating a classic stack-based buffer overflow condition. The use of unsafe strcpy function without proper bounds checking allows an attacker to overwrite adjacent stack memory, potentially corrupting return addresses, function pointers, or other critical program state information. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is categorized under the broader CWE-787 Out-of-bounds Write, and represents a fundamental flaw in memory management practices within embedded systems.
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 who can successfully exploit this vulnerability can manipulate the device's execution flow, potentially gaining unauthorized access to the hub's internal systems, modifying device configurations, or even using the compromised device as a pivot point for attacking other connected IoT devices within the network. The requirement for an authenticated HTTP request to trigger the vulnerability suggests that attackers may need to first obtain valid credentials or exploit another vulnerability to gain access to the device's management interface. However, once triggered, the buffer overflow can lead to complete system compromise, making this vulnerability particularly dangerous in home automation environments where these devices often serve as central control points for multiple connected systems.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term architectural improvements. The most direct solution involves patching the firmware to replace the unsafe strcpy usage with safer alternatives such as strncpy or strlcpy, which include bounds checking to prevent buffer overflows. Additionally, implementing proper input validation and sanitization mechanisms within the PubNub message handler can prevent malicious data from reaching the vulnerable code paths. Network segmentation and access control measures should be implemented to limit unauthorized access to the device's management interfaces, while also considering the deployment of intrusion detection systems that can monitor for suspicious PubNub traffic patterns. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, highlighting the need for both defensive measures and monitoring capabilities to detect and prevent exploitation attempts. Organizations should also consider implementing regular firmware update policies and conducting vulnerability assessments on IoT devices to identify and remediate similar issues before they can be exploited by threat actors.