CVE-2017-16295 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_schd, at 0x9d01a18c, the value for the `off` 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 • 02/04/2023
The vulnerability identified as CVE-2017-16295 represents a critical stack-based buffer overflow flaw within the Insteon Hub's PubNub message handling system. This issue specifically affects the "cc" channel functionality and manifests in firmware version 1012, creating a significant security risk for users of this smart home infrastructure. The vulnerability stems from improper input validation and dangerous string handling practices that allow attackers to manipulate memory layout through crafted PubNub messages. The flaw exists within the command processing mechanism where the system fails to properly check string lengths before copying data into fixed-size buffers, creating an exploitable condition that can be leveraged for arbitrary code execution or system compromise.
The technical implementation of this vulnerability occurs within the cmd s_schd function at memory address 0x9d01a18c where the system processes the `off` key parameter from incoming HTTP requests. The problematic code utilizes the unsafe `strcpy` function to copy data directly from the `off` key into a buffer located at stack offset $sp+0x270, which is only 16 bytes in size. This fundamental flaw violates secure coding practices and creates a direct path for attackers to overwrite adjacent stack memory, potentially corrupting return addresses, saved registers, or other critical program state information. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where insufficient bounds checking allows attackers to overwrite adjacent memory locations.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass full system compromise potential. An authenticated attacker with access to the PubNub service can craft malicious payloads that exploit this buffer overflow to execute arbitrary code on the Insteon Hub device, potentially gaining complete control over the smart home infrastructure. The vulnerability's exploitation requires only an authenticated HTTP request, making it accessible to attackers who can establish valid credentials or gain access to the PubNub communication channel. This creates a particularly dangerous scenario where attackers could manipulate home automation systems, potentially gaining access to security controls, monitoring devices, or other connected IoT components within the network ecosystem. The attack surface is further expanded by the fact that PubNub services are commonly used for real-time communication in IoT applications, making this vulnerability particularly concerning for widespread deployment.
Security mitigations for this vulnerability should focus on immediate firmware updates from Insteon to address the root cause through proper input validation and bounds checking mechanisms. The fix should replace the dangerous `strcpy` usage with safer alternatives such as `strncpy` or implement proper length validation before string copying operations. Additionally, network segmentation and access control measures should be implemented to limit exposure of the vulnerable PubNub channels and HTTP endpoints. The vulnerability demonstrates the importance of following secure coding guidelines and adheres to ATT&CK technique T1059.007 for Command and Scripting Interpreter, where attackers could leverage this vulnerability to execute malicious commands on the target system. Organizations should also implement network monitoring to detect anomalous PubNub traffic patterns that might indicate exploitation attempts, while ensuring that authentication mechanisms remain robust to prevent unauthorized access to the vulnerable service endpoints.