CVE-2018-3915 in SmartThings Hub STH-ETH-250
Summary
by MITRE
An exploitable stack-based buffer overflow vulnerability exists in the retrieval of database fields in the video-core HTTP server of the Samsung SmartThings Hub STH-ETH-250 - Firmware version 0.20.17. The strcpy call overflows the destination buffer, which has a size of 64 bytes. An attacker can send an arbitrarily long "bucket" value in order to exploit this vulnerability.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 05/17/2023
The vulnerability described in CVE-2018-3915 represents a critical stack-based 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 database field retrieval mechanism where the system fails to properly validate input length before performing string operations. The specific technical flaw manifests through an insecure use of the strcpy function which copies data from an unvalidated source without checking destination buffer boundaries. The destination buffer has a fixed size of only 64 bytes, creating a predictable overflow condition that can be exploited by malicious actors. The vulnerability is particularly concerning because it occurs within the HTTP server component, which is inherently exposed to network-based attacks and can be accessed by remote adversaries without requiring physical presence or elevated privileges.
The operational impact of this vulnerability extends significantly beyond simple buffer corruption, as it provides attackers with potential arbitrary code execution capabilities within the device's operating environment. The ability to send arbitrarily long "bucket" values means that an attacker can craft payloads that exceed the 64-byte buffer limit and overwrite adjacent stack memory, potentially corrupting return addresses and control flow information. This type of vulnerability directly maps to CWE-121 Stack-based Buffer Overflow, which is classified as a high-severity weakness in the CWE database and is commonly exploited in network-based attacks. The attack surface is further expanded by the fact that this vulnerability exists in a network-accessible HTTP server, making it susceptible to remote exploitation without requiring specialized tools or physical access to the device. The SmartThings Hub serves as a central networking point for home automation systems, meaning successful exploitation could provide attackers with access to an entire smart home ecosystem.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The most effective immediate solution involves patching the firmware to either implement proper input validation or replace the vulnerable strcpy function with a safer alternative such as strncpy or strlcpy that enforce buffer boundaries. Network administrators should implement firewall rules to restrict access to the affected HTTP server ports and consider segmenting the smart home network from the primary corporate or residential network. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter, as it enables attackers to execute arbitrary code on the target device. Additionally, the vulnerability demonstrates poor input validation practices that should be addressed through comprehensive security testing including fuzzing, static code analysis, and dynamic penetration testing. Organizations should also implement monitoring solutions to detect unusual network traffic patterns that might indicate exploitation attempts against IoT devices in their network infrastructure. The vulnerability highlights the critical need for robust software development practices and security testing in embedded systems, particularly those with network connectivity and control capabilities in home automation environments.