CVE-2017-16276 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_grp, at 0x9d0175f4, the value for the `gbt` key is copied using `strcpy` to the buffer at `$sp+0x280`.This buffer is 16 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/04/2023
The vulnerability described in CVE-2017-16276 represents a critical stack-based buffer overflow within the Insteon Hub's PubNub message handling system, specifically targeting the "cc" channel functionality. This flaw exists in firmware version 1012 and demonstrates a classic security weakness that has been documented under CWE-121, which describes stack-based buffer overflow conditions. The vulnerability occurs within the command processing logic of the hub's communication handler, where untrusted data from external PubNub service messages is directly copied into a fixed-size stack buffer without proper bounds checking.
The technical implementation of this vulnerability involves a specific function named cmd sn_grp located at memory address 0x9d0175f4 where the buffer overflow manifests. The system uses the `strcpy` function to copy data associated with the `gbt` key parameter into a stack buffer allocated at `$sp+0x280`. This buffer has a fixed size of only 16 bytes, making it extremely susceptible to overflow conditions when processing maliciously crafted input data. The use of `strcpy` without size validation creates an ideal scenario for attackers to overwrite adjacent stack memory locations, potentially corrupting program execution flow and enabling arbitrary code execution.
The operational impact of this vulnerability extends beyond simple buffer corruption, as it provides attackers with a pathway for remote code execution on the Insteon Hub device. The requirement for an authenticated HTTP request to trigger the vulnerability suggests that attackers would need to either obtain valid credentials or exploit additional authentication bypass mechanisms to reach this state. However, once triggered, the buffer overflow could allow attackers to overwrite return addresses, function pointers, or other critical stack data structures. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter execution, as successful exploitation could enable attackers to execute arbitrary commands on the compromised device.
The attack surface for this vulnerability is particularly concerning given that the Insteon Hub serves as a central communication hub for home automation systems, potentially providing attackers with access to connected smart home devices and networks. The exploitation of this vulnerability could enable attackers to gain persistent access to the home automation infrastructure, potentially leading to broader network compromise or physical security breaches. Security practitioners should consider this vulnerability in the context of IoT security frameworks and the specific risks associated with home automation devices that process external communications. The use of fixed-size buffers with unsafe string operations represents a common pattern that should be addressed through proper input validation, bounds checking, and the adoption of safer string handling functions such as `strncpy` or `snprintf` to prevent similar issues in future implementations.