CVE-2025-53558 Scanner

ZXHN-F660T and ZXHN-F660A routers are modem devices provided by ZTE, primarily used by internet service providers in their networks to connect homes and businesses to the internet. These devices are popular due to their reliability and feature set, including support for both DSL and Ethernet WAN options. They support multiple LAN configurations and various security protocols, making them suitable for both home and small enterprise environments. The hardware is designed for easy installation and configuration, with a web interface accessible for management. These routers often come pre-configured with default settings, branding themselves as a standardized solution across different markets. Due to their widespread use, they are subject to scrutiny and security testing by security researchers to ensure user safety.

The Default Credentials vulnerability in ZTE ZXHN-F660T/F660A exploits the fact that these routers use a common default username and password across installations. This security flaw arises when users or service providers fail to change these default settings, leaving the devices susceptible to unauthorized access. Attackers with knowledge of these default credentials can log in to the router interface and potentially alter configurations or gain network access. The vulnerability poses significant security risks, especially if the device serves as a gateway to other networked systems. Identifying and mitigating such vulnerabilities is crucial in maintaining network integrity and preventing unauthorized data access. Given its high severity, it requires immediate attention and remediation measures from users and administrators.

Technical details of the vulnerability reveal that an attacker sends a crafted HTTP POST request to the device's login page using the default credentials. If successful, the attacker would receive a redirect response indicating access to the management console. The request contains specific parameters necessary for authentication, including fields for username and password, typically set to 'admin'. The vulnerability is characterized by a positive match when the server response correlates with expected behavior following login with default credentials. Notably, the successful exploitation does not involve any negative matches such as incorrect login attempts, making it a straightforward attack vector.

Exploitation of the Default Credentials vulnerability could allow attackers to fully compromise affected routers. Once access is gained, malicious actors can modify important settings, change DNS configurations, or disable security features, potentially leading to further attacks like man-in-the-middle scenarios. It could also open doors for deploying harmful payloads over the connected networks, endangering the security of sensitive data. The lack of authentication fortification means affected devices are at continuous risk unless corrected, leading to potential data breaches or network disruptions.

REFERENCES

• https://nvd.nist.gov/vuln/detail/CVE-2025-53558
• https://jvn.jp/en/jp/JVN66546573/