CVE-2017-16254 in Hub 2245-222
Summary
by MITRE
An exploitable buffer overflow vulnerability exists in the PubNub message handler Insteon Hub 2245-222 - Firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriting arbitrary data. An attacker can send an authenticated HTTP request at 0x9d014e4c the value for the flg key is copied using strcpy to the buffer at $sp+0x270. This buffer is 16 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 08/03/2023
The vulnerability described in CVE-2017-16254 represents a critical stack-based buffer overflow within the PubNub message handler of the Insteon Hub 2245-222 device firmware version 1012. This flaw exists in the device's handling of authenticated HTTP requests through the PubNub messaging service, creating a pathway for remote code execution and system compromise. The vulnerability stems from improper input validation and unsafe string handling practices within the firmware's message processing logic, specifically affecting the device's security posture and operational integrity. The flaw manifests when an attacker crafts malicious commands that exploit the insecure use of strcpy function, which lacks bounds checking and directly copies user-supplied data into a fixed-size buffer without adequate size verification.
The technical implementation of this vulnerability involves a specific memory access pattern where the flg key value from an authenticated HTTP request is copied using strcpy to a buffer located at stack offset $sp+0x270. This buffer has a fixed size of only 16 bytes, making it extremely susceptible to overflow conditions when processing longer input data. The attack vector requires an authenticated HTTP request to be sent to the device, with the malicious payload targeting the specific memory location at 0x9d014e4c where the vulnerable function operates. This memory address represents a critical point in the device's execution flow where the buffer overflow occurs, potentially allowing attackers to overwrite adjacent stack memory, including return addresses and other critical program state information. The use of strcpy instead of safer alternatives like strncpy or strlcpy directly violates secure coding practices and creates a predictable exploitation pattern that aligns with common buffer overflow attack methodologies.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable complete system compromise and unauthorized access to the connected home automation network. An attacker who successfully exploits this vulnerability could gain arbitrary code execution privileges on the device, allowing them to manipulate the Insteon Hub's functionality, access connected devices, and potentially escalate their privileges to control the entire home automation ecosystem. The vulnerability's authentication requirement does not provide sufficient protection, as the attacker only needs to establish valid credentials to the PubNub service or gain access to legitimate device communication channels. This weakness creates a significant risk for residential and commercial installations where the Insteon Hub serves as a central control point for lighting, security, and environmental systems. The device's role in home automation makes this vulnerability particularly dangerous as it could allow attackers to disable security systems, manipulate lighting controls, or gain unauthorized access to other connected smart home devices.
Mitigation strategies for this vulnerability should focus on both immediate firmware updates and network-level defensive measures to protect against exploitation attempts. Device manufacturers should implement proper bounds checking and use secure string handling functions such as strncpy or strlcpy instead of strcpy to prevent buffer overflows. Network segmentation and access control measures should be implemented to limit exposure of the Insteon Hub to unauthorized users, including firewall rules that restrict access to the device's HTTP interfaces and PubNub communication ports. The vulnerability's classification as a stack-based buffer overflow aligns with CWE-121 which specifically addresses stack-based buffer overflow conditions, and the exploitation pattern matches ATT&CK technique T1059.007 for command and scripting interpreter. Additionally, implementing input validation controls and address space layout randomization (ASLR) would significantly reduce the exploitability of this vulnerability. Organizations should also consider network monitoring solutions that can detect anomalous PubNub traffic patterns that might indicate exploitation attempts, while maintaining regular firmware update schedules to address known vulnerabilities in IoT device ecosystems.