CVE-2017-16263 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 g_b, at 0x9d015a8c, 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 • 02/05/2023
The vulnerability described in CVE-2017-16263 represents a critical stack-based buffer overflow in the Insteon Hub's PubNub message handler component. This issue specifically affects the "cc" channel functionality within firmware version 1012, creating a significant security risk for users of this smart home device. The vulnerability stems from improper input validation and unsafe string handling practices that allow attackers to manipulate memory layout through crafted malicious payloads. The flaw exists within the command processing logic where the system fails to properly bounds-check input data before copying it into fixed-size buffers, directly violating fundamental security principles of secure coding practices.
The technical implementation of this vulnerability occurs at the assembly level within the cmd g_b function at memory address 0x9d015a8c where the value associated with the 'val' key is copied using the dangerous strcpy function. This particular implementation pattern creates a classic stack buffer overflow scenario where a 32-byte buffer located at $sp+0x2b0 receives data without proper bounds checking. The use of strcpy instead of safer alternatives like strlcpy or strncpy demonstrates a clear violation of secure coding guidelines and represents a CWE-121 stack-based buffer overflow vulnerability. When an attacker sends data exceeding the 32-byte buffer capacity, the excess data overflows into adjacent memory locations, potentially corrupting the stack frame and allowing for arbitrary code execution or system instability.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides attackers with a potential path to full system compromise of the Insteon Hub device. Since the vulnerability requires an authenticated HTTP request to trigger, it limits the attack surface but does not eliminate the risk entirely, as authentication credentials could potentially be obtained through other means. The attack vector through the PubNub service indicates that the vulnerability affects IoT devices that rely on cloud communication services, making it particularly concerning for smart home ecosystems. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and could enable lateral movement within home networks. The compromised device could serve as a pivot point for attackers to target other connected IoT devices or even establish persistent access to the home network.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from the vendor to address the buffer overflow condition through proper bounds checking and input validation. System administrators should implement network segmentation to isolate IoT devices from critical network segments and employ monitoring solutions to detect unusual PubNub traffic patterns. The vulnerability demonstrates the importance of input validation and secure coding practices, particularly in embedded systems and IoT devices where resource constraints may lead to the use of unsafe functions like strcpy. Organizations should also consider implementing network access controls to limit communication with PubNub services to only authorized devices and establish regular security assessments of IoT infrastructure to identify similar vulnerabilities in other connected devices. The fix should involve replacing the vulnerable strcpy call with a safe alternative that enforces buffer size limits, thereby preventing the overflow condition from occurring in the first place.