CVE-2018-3864 in SmartThings Hub STH-ETH-250
Summary
by MITRE
An exploitable buffer overflow vulnerability exists in the Samsung WifiScan handler of video-core's HTTP server of Samsung SmartThings Hub STH-ETH-250 - Firmware version 0.20.17. The strcpy overflows the destination buffer, which has a size of 40 bytes. An attacker can send an arbitrarily long "password" value in order to exploit this vulnerability.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/17/2023
The vulnerability identified as CVE-2018-3864 represents a critical buffer overflow flaw within the Samsung SmartThings Hub STH-ETH-250 device firmware version 0.20.17. This issue resides in the video-core HTTP server's WifiScan handler component, which processes network authentication requests from connected devices. The flaw manifests as a classic stack-based buffer overflow that occurs when the system processes user-supplied input through the password parameter field. The destination buffer allocated for this parameter is limited to only 40 bytes in size, creating an exploitable condition where malicious input can exceed this boundary and overwrite adjacent memory regions. This vulnerability specifically leverages the unsafe strcpy function which does not perform bounds checking, allowing arbitrary data to be copied into the fixed-size buffer without validation of input length. The attack vector requires an attacker to send a specially crafted HTTP request containing an excessively long password value to the affected device, making this a remote code execution vulnerability that could be exploited over the network without requiring physical access or authentication credentials.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw demonstrates characteristics of CWE-787, representing an out-of-bounds write condition that can result in arbitrary code execution or system crashes. From an operational perspective, this vulnerability presents a significant risk to IoT security infrastructure since the SmartThings Hub serves as a central controller for home automation systems, potentially providing attackers with persistent access to entire smart home networks. The vulnerability exists within the HTTP server component that handles authentication requests, meaning that successful exploitation could allow attackers to gain unauthorized access to network devices managed by the hub, potentially enabling lateral movement throughout connected IoT ecosystems. The use of strcpy instead of safer alternatives like strlcpy or strncpy represents a fundamental security flaw in the code implementation that violates secure coding practices recommended by the CERT Secure Coding Standards. The impact extends beyond simple device compromise as the SmartThings Hub typically controls multiple connected devices including sensors, locks, cameras, and lighting systems, making this vulnerability a potential gateway for comprehensive home network infiltration.
The operational impact of CVE-2018-3864 extends significantly beyond traditional device compromise scenarios, as it represents a critical weakness in IoT security infrastructure that could enable sophisticated attack chains. Attackers could potentially leverage this vulnerability to execute arbitrary code on the device, gain persistent access to the home network, or even use the compromised hub as a pivot point for attacking other connected systems within the network perimeter. The vulnerability's remote exploitability means that attackers could target devices from anywhere on the internet without requiring physical proximity or network access, making it particularly dangerous for residential and commercial IoT deployments. From an ATT&CK framework perspective, this vulnerability maps to multiple techniques including T1059 for command execution, T1046 for network service scanning, and T1071 for application layer protocol usage. The exploitation process would likely involve crafting HTTP requests with oversized password parameters, potentially utilizing techniques such as return-oriented programming or stack pivoting to achieve code execution. Security researchers have noted that similar vulnerabilities in IoT devices often remain unpatched for extended periods due to the difficulty in managing firmware updates for distributed consumer devices, creating long-term exposure windows for attackers. The vulnerability also demonstrates the broader challenge of securing embedded systems where legacy code patterns and insufficient input validation remain common, particularly in devices where security was not initially prioritized during development lifecycle phases. Organizations should consider implementing network segmentation and monitoring for unusual HTTP traffic patterns that might indicate exploitation attempts against IoT infrastructure, while also recognizing that the true scope of impact extends beyond individual device compromise to encompass entire connected ecosystems that depend on secure gateway functionality.