CVE-2018-3874 in SmartThings Hub STH-ETH-250
Summary
by MITRE
An exploitable buffer overflow vulnerability exists in the credentials handler of video-core's HTTP server of Samsung SmartThings Hub STH-ETH-250-Firmware version 0.20.17. The strncpy overflows the destination buffer, which has a size of 32 bytes. An attacker can send an arbitrarily long "accessKey" value in order to exploit this vulnerability.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/17/2023
The vulnerability identified as CVE-2018-3874 represents a critical buffer overflow flaw within the video-core HTTP server component of Samsung SmartThings Hub STH-ETH-250 devices running firmware version 0.20.17. This issue resides in the credentials handling mechanism where improper input validation leads to a classic buffer overflow condition. The flaw manifests when the system processes authentication requests containing excessively long access key values, creating a scenario where memory corruption can occur beyond the intended 32-byte buffer boundaries. The vulnerability stems from the use of strncpy function without adequate bounds checking, allowing attackers to overwrite adjacent memory locations and potentially execute arbitrary code or cause system instability. This represents a fundamental security failure in input sanitization and memory management practices within the embedded firmware system.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-121, which describes buffer overflow conditions where insufficient bounds checking allows data to be written beyond allocated memory regions. The specific implementation flaw occurs when the strncpy function processes an accessKey parameter that exceeds the 32-byte destination buffer capacity, causing data to spill into adjacent memory locations. This overflow can overwrite critical program variables, return addresses, or function pointers, enabling attackers to manipulate program execution flow. The vulnerability's impact is amplified by the fact that the accessKey parameter is directly exposed through HTTP requests, making exploitation accessible over the network without requiring physical access to the device. Attackers can leverage this weakness to achieve remote code execution or system compromise, potentially gaining full administrative control over the SmartThings Hub device.
The operational consequences of this vulnerability extend beyond simple system crashes or denial of service conditions. When exploited successfully, the buffer overflow can provide attackers with unauthorized access to the device's core functionalities, including the ability to manipulate smart home automation settings, access network credentials, or establish persistent backdoors within the home automation ecosystem. The SmartThings Hub serves as a central control point for numerous IoT devices, making this vulnerability particularly dangerous as it could enable attackers to compromise an entire smart home network. The vulnerability's accessibility through standard HTTP protocols means that attackers can exploit it remotely, potentially affecting thousands of devices simultaneously if they share similar firmware versions. This exposure creates significant risks for personal privacy and home security, as the compromised device could serve as a gateway for further attacks within the network infrastructure.
Mitigation strategies for CVE-2018-3874 should focus on immediate firmware updates from Samsung to address the root cause of the buffer overflow condition. Organizations and individuals should implement network segmentation to limit access to the SmartThings Hub device, particularly restricting direct internet exposure. Network monitoring solutions should be deployed to detect unusual HTTP traffic patterns that might indicate exploitation attempts, including unusually long accessKey parameters. Additional protective measures include implementing strong access controls for the device's administrative interfaces, regularly auditing device configurations, and maintaining detailed network logs for forensic analysis. Security professionals should consider deploying intrusion detection systems specifically configured to identify patterns associated with buffer overflow exploitation attempts. The vulnerability also highlights the importance of secure coding practices and input validation in embedded systems, particularly emphasizing the need for bounds checking in memory management operations. Organizations should conduct comprehensive vulnerability assessments of their IoT infrastructure to identify similar weaknesses in other networked devices that might be vulnerable to comparable buffer overflow conditions.