CVE-2018-14794 in Alpha5 Smart Loader
Summary
by MITRE
Fuji Electric Alpha5 Smart Loader Versions 3.7 and prior. The device does not perform a check on the length/size of a project file before copying the entire contents of the file to a heap-based buffer.
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Analysis
by VulDB Data Team • 03/28/2020
The vulnerability identified as CVE-2018-14794 affects Fuji Electric Alpha5 Smart Loader devices running version 3.7 and earlier, representing a critical buffer overflow condition that exposes the system to potential exploitation. This flaw resides in the device's handling of project files, where the system fails to validate the size of incoming data before processing it, creating an opportunity for malicious actors to manipulate the device's memory structure. The issue stems from inadequate input validation mechanisms that should have enforced bounds checking on file sizes to prevent heap-based buffer overflows.
The technical implementation of this vulnerability demonstrates a classic buffer management flaw where the system assumes all project files will fit within predetermined memory boundaries without performing size verification. When a specially crafted project file exceeds the allocated buffer space, the system continues to copy data beyond the intended memory limits, causing memory corruption that can lead to arbitrary code execution or system instability. This type of vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions, though the heap-based nature of this implementation makes it particularly concerning for embedded systems. The flaw operates at the application layer where file processing occurs, making it accessible through legitimate device interfaces that accept project file uploads.
The operational impact of this vulnerability extends beyond simple system crashes or denial of service conditions, as it creates a potential entry point for attackers to gain unauthorized control over the device. An attacker could craft a malicious project file that, when processed by the vulnerable Smart Loader, would overwrite adjacent memory locations with malicious code or manipulate system behavior to execute unintended commands. This represents a significant security risk for industrial control systems where these devices may be connected to critical infrastructure, potentially allowing for lateral movement within network segments or complete system compromise. The vulnerability's exploitation aligns with ATT&CK technique T1059, which involves the execution of malicious code through command and scripting interpreters, and T1068, which focuses on the abuse of legitimate privileges to gain system access.
Mitigation strategies for this vulnerability require immediate implementation of input validation controls that enforce strict size limits on project files before processing begins. System administrators should implement firmware updates from Fuji Electric that address the buffer overflow condition through proper bounds checking mechanisms. Network segmentation and access controls should be enforced to limit who can upload project files to these devices, reducing the attack surface for potential exploitation. Additionally, regular security assessments should include verification that all device components properly validate input data to prevent similar buffer overflow conditions. The remediation approach should follow established security practices outlined in NIST SP 800-144 for embedded systems security, ensuring that all input handling mechanisms incorporate proper validation and error detection to prevent memory corruption scenarios.