CVE-2018-3912 in SmartThings Hub STH-ETH-250
Summary
by MITRE
On Samsung SmartThings Hub STH-ETH-250 devices with firmware version 0.20.17, the video-core process insecurely extracts the fields from the "shard" table of its SQLite database, leading to a buffer overflow on the stack. The strcpy call overflows the destination buffer, which has a size of 128 bytes. An attacker can send an arbitrarily long "secretKey" value in order to exploit this vulnerability.
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Analysis
by VulDB Data Team • 03/17/2020
The vulnerability identified as CVE-2018-3912 affects Samsung SmartThings Hub STH-ETH-250 devices running firmware version 0.20.17, representing a critical security flaw in the device's video-core process implementation. This issue stems from improper input validation and memory management practices within the application's handling of database records, specifically targeting the shard table structure. The vulnerability manifests as a classic buffer overflow condition that occurs during the extraction of data fields from an SQLite database, where the application fails to properly validate the length of incoming data before copying it into fixed-size memory buffers.
The technical exploitation of this vulnerability relies on the insecure use of the strcpy function, which performs no bounds checking when copying data from the database shard table into a destination buffer of only 128 bytes. This primitive memory manipulation error creates an exploitable condition where an attacker can craft malicious input containing an arbitrarily long secretKey value that exceeds the buffer capacity. When the video-core process attempts to copy this oversized value into the 128-byte destination buffer, it overflows the stack space allocated for the operation, potentially allowing for arbitrary code execution or system compromise.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it represents a remote code execution threat that could enable attackers to gain full control over the SmartThings Hub device. This compromises the entire home automation ecosystem managed by the device, potentially allowing unauthorized access to connected smart home devices, data exfiltration from the network, and lateral movement within the local network infrastructure. The vulnerability's exploitation requires minimal privileges since the device operates with elevated permissions necessary for its core functionality, making the attack surface particularly dangerous for residential and commercial smart home deployments.
Security practitioners should implement immediate mitigations including firmware updates from Samsung to address the buffer overflow condition in the video-core process, along with network segmentation and monitoring of database access patterns. The vulnerability aligns with CWE-121, which catalogs stack-based buffer overflow conditions, and represents a clear violation of secure coding practices that should be addressed through input validation and proper memory management. Organizations should also consider implementing intrusion detection systems to monitor for anomalous database access patterns that might indicate exploitation attempts, while adhering to ATT&CK framework principles for threat hunting and incident response. The vulnerability demonstrates the importance of secure coding practices in IoT devices and the critical need for proper bounds checking in embedded systems processing database inputs.