CVE-2017-16299 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_raw, at 0x9d01aad8, the value for the `d` key is copied using `strcpy` to the buffer at `$sp+0x334`.This buffer is 100 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/04/2023
The CVE-2017-16299 vulnerability represents a critical stack-based buffer overflow flaw in the Insteon Hub's PubNub message handling system, specifically affecting the "cc" channel functionality within firmware version 1012. This vulnerability resides in the command processing logic where the system fails to properly validate input lengths before copying data into fixed-size buffers, creating an exploitable condition that can be leveraged by remote attackers. The flaw manifests in the sn_raw command handler at address 0x9d01aad8, where the system uses the insecure strcpy function to copy data from the 'd' key parameter into a stack buffer of only 100 bytes. This primitive copying operation without bounds checking creates a classic buffer overflow condition that can overwrite adjacent stack memory and potentially allow arbitrary code execution.
The technical implementation of this vulnerability demonstrates a clear violation of secure coding practices, specifically aligning with CWE-121, which addresses stack-based buffer overflow conditions. The vulnerability operates through the PubNub messaging service, which serves as the communication channel between the Insteon Hub and external systems, making it particularly dangerous as it can be exploited remotely without requiring physical access to the device. The attack vector requires an authenticated HTTP request to trigger the vulnerable code path, indicating that the system may have some form of authentication mechanism that must be bypassed or successfully exploited to gain access to the vulnerable handler. The specific memory layout shows that the buffer located at $sp+0x334 is insufficient for the data being copied, creating a scenario where any input exceeding 100 bytes will overwrite adjacent stack variables and potentially corrupt the return address, leading to potential code execution control flow hijacking.
The operational impact of this vulnerability extends beyond simple data corruption, as it represents a significant security risk for home automation systems that rely on the Insteon Hub for device control and monitoring. The ability to trigger a buffer overflow through the PubNub service means that attackers could potentially execute arbitrary code on the device, leading to complete system compromise and unauthorized control of connected home automation devices. This vulnerability directly maps to ATT&CK technique T1059.007, which covers the execution of commands through scripting languages, as the exploitation could lead to command execution capabilities. The attack surface is particularly concerning given that the Insteon Hub typically operates in residential environments where the compromise of such a device could lead to unauthorized access to home security systems, lighting controls, heating systems, and other critical infrastructure components. The vulnerability's exploitation requires an authenticated HTTP request, suggesting that the attacker must first obtain valid credentials or exploit another authentication bypass mechanism, but once achieved, the impact could be severe.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Insteon to address the buffer overflow condition through proper input validation and bounds checking. The system should implement proper bounds checking before any string operations, replacing the insecure strcpy function with safer alternatives like strncpy or strlcpy that enforce maximum buffer limits. Additionally, implementing input validation for all parameters received through the PubNub service would prevent oversized data from reaching the vulnerable code paths. Network-level mitigations could include restricting access to the PubNub service endpoints and implementing rate limiting to prevent abuse of the authenticated HTTP request functionality. The solution should also incorporate proper error handling and logging to detect potential exploitation attempts, as well as consider implementing stack canaries or other memory protection mechanisms to detect and prevent exploitation attempts. Organizations should also conduct comprehensive security assessments of their home automation systems to identify similar vulnerabilities in other connected devices and ensure proper network segmentation to limit the potential impact of such compromises.