CVE-2026-80156 in SLC8000
Summary
by MITRE • 09/22/2026
Lantronix SLC8000 before firmware v9.7.0.5, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a path traversal vulnerability in the web management portal upload endpoint that allows authenticated attackers to write arbitrary data to any location on the device's filesystem, leading to remote code execution. The upload filename validation strips backslash characters but does not subsequently check for forward slashes when a backslash is detected; by supplying a filename containing both characters an attacker writes outside the intended upload directory to any writable path. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
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Analysis
by VulDB Data Team • 09/22/2026
The identified security flaw resides within the web management portal's file upload functionality across several Lantronix industrial networking products, specifically affecting SLC8000 units running firmware prior to version 9.7.0.5, EMG8500 and EMG7500 devices with firmware earlier than v9.7.0.1, and all existing versions of the SLB882, SLCx-03, and SLCx-02 series. This vulnerability is classified as a path traversal issue that permits authenticated attackers to bypass intended file system restrictions by manipulating input filenames during the upload process. The core technical failure stems from an incomplete sanitization routine where the application logic attempts to neutralize directory separators but does so in a flawed manner. Specifically, the validation mechanism strips backslash characters from the uploaded filename string but fails to perform a subsequent check for forward slash characters when such anomalies are detected or processed. This asymmetric handling of path delimiters creates a predictable bypass vector that allows an attacker to construct filenames containing both character types to escape the designated upload directory and write arbitrary data to any location on the device's local filesystem where write permissions exist.
From a technical perspective, this flaw aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory, as the application fails to enforce strict boundaries around user-controlled input before using it in file system operations. The vulnerability is further contextualized by ATT&CK technique T1059 Command and Scripting Interpreter or potentially T1036 Masquerading if the uploaded files are designed to mimic legitimate system binaries for persistence, although the primary impact here is direct code execution via arbitrary file write capabilities. Because industrial control systems often rely on these devices for critical communication between supervisory software and field-level equipment, the ability to execute remote code represents a severe compromise of the underlying infrastructure. The attacker does not need elevated privileges beyond standard authentication access to exploit this condition, which lowers the barrier to entry significantly compared to unauthenticated exploits but remains highly dangerous in environments where user accounts may be shared or weakly secured.
The operational impact of this vulnerability is profound and extends far beyond the immediate compromise of the network device itself. By achieving remote code execution through arbitrary file writes, an attacker gains complete control over the affected hardware, resulting in a total loss of confidentiality, integrity, and availability for that specific node. Confidentiality is compromised as sensitive configuration data, credentials stored on the device, or intercepted traffic can be exfiltrated. Integrity is undermined because the attacker can modify system binaries, configuration files, or logging mechanisms to hide their presence or alter network behavior without detection. Availability is threatened through the potential deletion of critical system files or the deployment of ransomware-like payloads that render the device inoperable. Furthermore, given the role these devices play as gateways between Ethernet networks and serial-connected industrial equipment such as PLCs, HMIs, and sensors, a compromised Lantronix unit can serve as a pivot point for lateral movement into the broader operational technology network. This enables attackers to disrupt physical processes, manipulate sensor readings, or halt production lines by sending malicious commands through the serial interface after gaining control of the gateway device.
Mitigation strategies must prioritize immediate firmware updates where available. Administrators should upgrade SLC8000 devices to version 9.7.0.5 or later and EMG8500/EMG7500 units to v9.7.0.1 or higher, as these versions contain the necessary patches for this path traversal flaw. For legacy systems such as SLB882, SLCx-03, and SLCx-02 where no patched firmware exists, organizations must implement compensating controls to reduce risk exposure. These measures include restricting access to the web management portal through network segmentation so that only authorized IP addresses can reach the device's administrative interface. Additionally, enforcing strong authentication policies with multi-factor authentication wherever possible reduces the likelihood of credential compromise leading to exploitation. Network monitoring tools should be configured to detect anomalous file upload patterns or unusual outbound connections from these devices, which may indicate active exploitation attempts. Regular vulnerability assessments and penetration testing focused on industrial IoT components are essential to identify similar misconfigurations before they can be leveraged by adversaries targeting critical infrastructure.