CVE-2017-16259 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_auth, at 0x9d015430, the value for the `usr` key is copied using `strcpy` to the buffer at `$sp+0x290`.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-2017-16259 represents a critical stack-based buffer overflow in the Insteon Hub's PubNub message handling system, specifically affecting the "cc" channel functionality within firmware version 1012. This flaw exists within the command authentication mechanism where the system processes user credentials through the s_auth function, creating an exploitable condition that can be leveraged by malicious actors to gain unauthorized access to the device. The vulnerability manifests when the system receives specially crafted commands through the PubNub messaging service, which serves as the communication channel between the hub and external services.
The technical implementation of this vulnerability stems from the insecure use of the strcpy function in the s_auth function at address 0x9d015430, where the value associated with the 'usr' key is copied directly into a buffer located at stack pointer offset +0x290. This buffer has a fixed size of only 32 bytes, making it susceptible to overflow when user input exceeds this limit. The flaw directly maps to CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows data to overwrite adjacent stack memory locations. The use of strcpy without proper bounds verification creates a classic buffer overflow scenario where an attacker can overwrite return addresses, saved registers, or other critical stack data structures.
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 affected device. When an authenticated HTTP request is sent to trigger the vulnerability, the attacker can craft payloads that overwrite the stack frame to redirect execution flow, potentially leading to complete system compromise. This represents a significant risk for home automation systems, as the Insteon Hub serves as a central control point for smart home devices, making successful exploitation potentially catastrophic for user security and privacy. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, where attackers can leverage buffer overflows to inject malicious code, and T1078 for Valid Accounts, as the attack requires authentication to trigger the vulnerable code path.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Insteon to address the buffer overflow condition through proper bounds checking and use of safer string handling functions such as strlcpy or strncpy instead of strcpy. Network segmentation and access controls should be implemented to limit exposure of the hub to untrusted networks, while monitoring should be deployed to detect anomalous PubNub traffic patterns that might indicate exploitation attempts. Additionally, organizations should conduct thorough security assessments of their smart home infrastructure to identify other potentially vulnerable devices that might share similar architectural flaws, ensuring comprehensive protection against similar buffer overflow vulnerabilities that could compromise the entire home automation ecosystem.