CVE-2018-3916 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 136 bytes. An attacker can send an arbitrarily long 'directory' value in order to exploit this vulnerability. An attacker can send an HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 03/19/2020
The vulnerability described in CVE-2018-3916 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 handling of database field retrieval operations where the system fails to properly validate input length before performing string operations. The specific technical flaw manifests through an unsafe strcpy function call that copies data into a destination buffer of only 136 bytes without adequate bounds checking, creating a predictable overflow condition that can be exploited by remote attackers.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with the capability to manipulate the device's memory layout and potentially gain unauthorized access to the underlying system. The attack vector requires only a single HTTP request containing a specially crafted 'directory' parameter with an arbitrarily long value, making exploitation both accessible and remotely feasible. This vulnerability directly aligns with CWE-121 Stack-based Buffer Overflow, which classifies such issues as critical due to their potential for arbitrary code execution and system compromise. The flaw demonstrates poor input validation practices that violate fundamental security principles and can be mapped to ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable attackers to execute arbitrary commands on the affected device.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Samsung to address the specific buffer overflow condition in the video-core HTTP server. System administrators should implement network segmentation and access controls to limit exposure of the SmartThings Hub to untrusted networks. Additional defensive measures include deploying network intrusion detection systems to monitor for suspicious HTTP requests containing unusually long directory parameters and implementing web application firewalls to filter malicious input. The vulnerability highlights the importance of proper input validation and bounds checking in embedded systems, particularly those handling user-provided data through HTTP interfaces. Organizations should conduct thorough security assessments of their IoT device inventories to identify similar vulnerabilities in other embedded systems that may be susceptible to similar stack-based buffer overflow attacks.