CVE-2018-3913 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 32 bytes. An attacker can send an arbitrarily long "accessKey" value in order to exploit this vulnerability.
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Analysis
by VulDB Data Team • 05/17/2023
The vulnerability identified as CVE-2018-3913 represents a critical stack-based buffer overflow in the Samsung SmartThings Hub STH-ETH-250 device firmware version 0.20.17. This flaw exists within the video-core HTTP server component responsible for handling database field retrieval operations. The vulnerability stems from improper input validation and memory management practices that allow malicious actors to exploit the system through crafted HTTP requests. The specific technical implementation involves a vulnerable strcpy function call that does not perform adequate bounds checking before copying data into a destination buffer of fixed size 32 bytes. This fundamental flaw in memory handling creates an exploitable condition where an attacker can overflow the stack buffer and potentially overwrite adjacent memory locations including return addresses and control data. The vulnerability is particularly concerning as it affects a network-connected IoT device that serves as a central hub for smart home automation systems, making it an attractive target for attackers seeking persistent access to home networks.
The operational impact of this vulnerability extends beyond simple buffer overflow exploitation, as it provides attackers with potential pathways for privilege escalation and system compromise. The use of strcpy without proper bounds checking represents a classic CWE-121 buffer overflow vulnerability pattern that has been documented extensively in cybersecurity literature. Attackers can leverage this vulnerability by sending specially crafted HTTP requests containing an arbitrarily long "accessKey" value that exceeds the 32-byte buffer capacity. This allows for arbitrary code execution on the affected device, potentially enabling full system compromise. The attack surface is further expanded by the fact that the SmartThings Hub serves as a central communication point for numerous smart home devices, meaning successful exploitation could provide attackers with access to an entire smart home ecosystem. The vulnerability's exploitability is enhanced by the fact that it requires no authentication, making it particularly dangerous as attackers can exploit it remotely without requiring physical access or legitimate credentials.
Mitigation strategies for CVE-2018-3913 must address both immediate defensive measures and long-term architectural improvements to prevent similar vulnerabilities from occurring in future implementations. Organizations should prioritize firmware updates from Samsung to address the specific buffer overflow condition, while also implementing network segmentation to limit the potential impact of successful exploitation. Network monitoring solutions should be deployed to detect anomalous HTTP traffic patterns that may indicate exploitation attempts targeting this specific vulnerability. The implementation of input validation controls, including bounds checking and proper memory management practices, should be enforced throughout all software development processes to prevent similar issues in future versions. From an ATT&CK framework perspective, this vulnerability maps to techniques involving command and control communication, privilege escalation, and persistence mechanisms that attackers can leverage once they achieve initial system compromise. Security teams should also consider implementing intrusion detection systems that can identify and block malicious HTTP requests containing oversized accessKey parameters, as well as conducting regular vulnerability assessments to identify similar buffer overflow conditions in other networked devices within their smart home environments.