CVE-2017-16267 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 0x9d016578, the value for the `val` 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 identified as CVE-2017-16267 represents a critical stack-based buffer overflow within the PubNub message handler component of Insteon Hub firmware version 1012. This flaw exists specifically within the "cc" channel processing functionality, making it particularly dangerous as it leverages the PubNub messaging service which is commonly used for real-time communication between IoT devices and their control systems. The vulnerability stems from improper input validation and dangerous string handling practices that have been classified under CWE-121 as stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the stack.
The technical implementation of this vulnerability occurs within the cmd s_b function at memory address 0x9d016578, where the system processes the `val` key value from incoming PubNub messages. The flaw manifests when the application employs the unsafe strcpy function to copy user-supplied data directly into a stack buffer that is only 32 bytes in size. This primitive copy operation lacks any size validation or bounds checking mechanisms that would normally prevent overwriting adjacent memory regions. The buffer located at $sp+0x2b0 provides insufficient space for potentially malicious input, creating a predictable overflow condition that can be exploited to overwrite return addresses, saved registers, and other critical stack data structures.
The operational impact of this vulnerability extends beyond simple denial of service scenarios as it presents a complete remote code execution vector for authenticated attackers. Since the vulnerability requires only an authenticated HTTP request to trigger, an attacker who has gained access to the Insteon Hub's administrative credentials or has compromised a legitimate PubNub communication channel can exploit this flaw to execute arbitrary code on the affected device. This represents a significant compromise of the IoT device's security posture, potentially allowing attackers to gain full control over the hub's operations, modify device configurations, or establish persistent backdoors for continued access. The attack surface is further expanded due to the nature of PubNub as a real-time messaging platform, which means the vulnerability could be exploited through various communication channels without requiring direct network access to the device itself.
Mitigation strategies for CVE-2017-16267 should focus on immediate firmware updates from Insteon to address the root cause through proper bounds checking and safe string handling practices. Organizations should implement network segmentation and access controls to limit the exposure of Insteon Hub devices to untrusted networks, while also monitoring for unusual PubNub traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of secure coding practices and adherence to the principle of least privilege, as highlighted in MITRE ATT&CK framework under the T1059 technique for command and scripting interpreter. Additionally, network intrusion detection systems should be configured to monitor for specific patterns in HTTP request payloads that match the vulnerable strcpy usage pattern, providing an additional layer of defense against exploitation attempts.