Overview
In this post, we will examine a critical vulnerability, CVE-2025-43986, discovered in the KuWFi GC111 GC111-GL-LM321_V3.0_20191211 devices. This vulnerability is particularly alarming due to its potential for system compromise or data leakage. KuWFi GC111 devices, used worldwide, have the TELNET service enabled by default and exposed over the WAN interface without authentication, posing a significant risk to users’ data and system security. It is crucial to address this issue promptly to prevent potential attacks and protect your systems and data.
Vulnerability Summary
CVE ID: CVE-2025-43986
Severity: Critical (CVSS 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
KuWFi GC111 | GC111-GL-LM321_V3.0_20191211
How the Exploit Works
The vulnerability lies in the default configuration of the KuWFi GC111 devices, where the TELNET service is enabled by default and exposed over the WAN interface without requiring any authentication. This setup allows potential attackers to remotely access the device over the internet via the telnet protocol. Since there is no authentication layer, the attacker can gain full control of the device, leading to system compromise or data leakage.
Conceptual Example Code
Below is a conceptual example of how this vulnerability might be exploited using telnet command:
telnet target_device_ip
In the above example, `target_device_ip` is the IP address of the vulnerable KuWFi GC111 device. Since the device does not require authentication for TELNET service, an attacker can directly access the device and execute shell commands. This example illustrates the severity of this vulnerability and underscores the need for immediate remediation.