CVE-2017-16281 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_net, at 0x9d018234, the value for the `sub` 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-2017-16281 represents a critical stack-based buffer overflow in the Insteon Hub device firmware version 1012, specifically affecting the PubNub message handler for the "cc" channel. This flaw resides within the network communication processing logic of the hub's embedded system, creating a pathway for remote code execution through carefully crafted malicious inputs. The vulnerability stems from improper input validation and unsafe string handling practices that allow attackers to overwrite memory regions beyond the intended buffer boundaries. The affected component processes messages through the PubNub service, which serves as a communication bridge between the hub and external devices, making this a particularly dangerous exposure given the hub's role as a central controller for home automation systems.
The technical implementation of this vulnerability occurs within the cmd s_net function at memory address 0x9d018234 where the system employs the unsafe strcpy function to copy data from the `sub` key parameter into a buffer located at stack pointer offset $sp+0x2b0. This buffer allocation is insufficiently sized at only 32 bytes, creating a clear mismatch between input data requirements and available memory space. When an attacker sends a specially crafted HTTP request containing a `sub` value longer than 32 bytes, the strcpy operation overflows the designated buffer, potentially corrupting adjacent stack memory, including return addresses and function parameters. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a high-risk vulnerability in the Common Weakness Enumeration catalog due to its potential for arbitrary code execution and system compromise.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with the capability to execute arbitrary code on the Insteon Hub device with the privileges of the running process. Given that the hub controls home automation systems including lighting, security, and climate control devices, successful exploitation could result in complete system takeover, unauthorized access to connected devices, and potential data exfiltration from the home network. The requirement for an authenticated HTTP request to trigger this vulnerability suggests that attackers would need to either obtain valid credentials or exploit additional authentication bypass mechanisms, but the low barrier to exploitation through the unsafe string handling makes this a particularly concerning weakness. The vulnerability also aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as it allows for command execution through the compromised communication channel.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Insteon to address the buffer overflow through proper input validation and memory management practices. System administrators should implement network segmentation to isolate the Insteon Hub from critical network segments and establish monitoring for unusual PubNub traffic patterns that might indicate exploitation attempts. The fix should replace the unsafe strcpy function with safer alternatives such as strncpy or strlcpy that enforce buffer boundaries, and implement proper input validation to ensure that all incoming data conforms to expected size limits. Additionally, network-based intrusion detection systems should be configured to monitor for HTTP requests containing suspicious payload lengths in the `sub` parameter, and regular security audits should verify that similar buffer overflow vulnerabilities do not exist in other components of the hub's firmware. Organizations should also consider implementing secure coding practices that align with industry standards such as the CERT C Secure Coding Standard, which specifically recommends avoiding unsafe string functions like strcpy in favor of their safer counterparts.