Nexxt NCM-X1800 up to 1.2.7 Telnet Service /web/um_open_telnet.cgi hard-coded credentials

Summaryinfo

A vulnerability identified as critical has been detected in Nexxt NCM-X1800 up to 1.2.7. Impacted is an unknown function of the file /web/um_open_telnet.cgi of the component Telnet Service. The manipulation leads to hard-coded credentials. This vulnerability is traded as CVE-2025-52376. It is possible to initiate the attack remotely. Furthermore, there is an exploit available.

Detailsinfo

A vulnerability was found in Nexxt NCM-X1800 up to 1.2.7 and classified as critical. This issue affects some unknown functionality of the file /web/um_open_telnet.cgi of the component Telnet Service. The manipulation with an unknown input leads to a hard-coded credentials vulnerability. Using CWE to declare the problem leads to CWE-798. The product contains hard-coded credentials, such as a password or cryptographic key, which it uses for its own inbound authentication, outbound communication to external components, or encryption of internal data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An authentication bypass vulnerability in the /web/um_open_telnet.cgi endpoint in Nexxt Solutions NCM-X1800 Mesh Router firmware UV1.2.7 and below, allowing an attacker to remotely enable the Telnet service without authentication, bypassing security controls. The Telnet server is then accessible with hard-coded credentials, allowing attackers to gain administrative shell access and execute arbitrary commands on the device.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-52376 since 06/16/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. MITRE ATT&CK project uses the attack technique T1110.001 for this issue.

The exploit is available at github.com. It is declared as proof-of-concept.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-21439). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Nexxt

Name

• NCM-X1800

Version

• 1.2.0
• 1.2.1
• 1.2.2
• 1.2.3
• 1.2.4
• 1.2.5
• 1.2.6
• 1.2.7

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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