Overview
CVE-2025-52376 represents a severe vulnerability that affects the firmware of the Nexxt Solutions NCM-X1800 Mesh Router. It exposes a loophole in the /web/um_open_telnet.cgi endpoint, allowing unauthorized access to the Telnet service without authentication. This exploit can provide the attacker with administrative shell access and the ability to execute arbitrary commands on the device.
This vulnerability is highly concerning due to its potential impact on both individual users and corporations. With unauthorized access, an attacker can compromise the system, leading to potential data leakage or total system control. Therefore, understanding and mitigating this vulnerability is of utmost importance for cybersecurity.
Vulnerability Summary
CVE ID: CVE-2025-52376
Severity: Critical (9.8 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and data leakage
Affected Products
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Product | Affected Versions
Nexxt Solutions NCM-X1800 Mesh Router | firmware UV1.2.7 and below
How the Exploit Works
The vulnerability resides in the /web/um_open_telnet.cgi endpoint of the Nexxt Solutions NCM-X1800 Mesh Router firmware. An attacker can exploit this vulnerability by sending a specific network request to this endpoint. Upon receiving the request, the router unintentionally enables the Telnet service, bypassing any security controls.
The Telnet server, once enabled, is accessible with hard-coded credentials, providing an attacker with administrative shell access on the device. This level of access allows the attacker to execute arbitrary commands, potentially compromising the entire system.
Conceptual Example Code
Below is a conceptual HTTP request example that an attacker might employ to exploit the vulnerability:
GET /web/um_open_telnet.cgi HTTP/1.1
Host: target_router_ipOnce the Telnet service is enabled, an attacker can log in using hard-coded credentials:
telnet target_router_ip
Username: admin
Password: adminThe above example is only conceptual and does not represent actual exploit code. The actual payload would depend on the specific device configuration and the goals of the attacker.