CVE-2025-53756 is a high-severity vulnerability affecting the Digisol XPON ONU Wi-Fi Router model DG-GR6821AC, specifically version V3.2.XX. The core issue is the cleartext transmission of sensitive information, namely user credentials, via the router's web management interface. This vulnerability is categorized under CWE-319, which refers to the cleartext transmission of sensitive data. Because the credentials are transmitted without encryption, a remote attacker positioned on the same network or able to intercept network traffic can capture these credentials through network sniffing techniques. Exploiting this vulnerability does not require any authentication, user interaction, or elevated privileges, making it relatively easy to exploit. Once the attacker obtains the credentials, they can gain unauthorized access to the router's management interface, potentially allowing them to alter configurations, disrupt network services, or pivot to other devices within the network. The CVSS 4.0 base score of 8.7 reflects the high impact and ease of exploitation, with network attack vector, no required privileges, and no user interaction. The vulnerability does not affect confidentiality, integrity, or availability directly beyond the compromise of the router's management interface, but the router's central role in network operations means that unauthorized access can have significant downstream effects. No patches or fixes are currently linked, and no known exploits are reported in the wild as of the publication date (July 16, 2025).

For European organizations, this vulnerability poses a significant risk, especially for enterprises and service providers using Digisol XPON ONU Wi-Fi Routers in their network infrastructure. Unauthorized access to the router management interface can lead to network misconfigurations, interception or redirection of traffic, and potential lateral movement within the network. This can compromise the confidentiality and integrity of sensitive organizational data and disrupt availability of network services. Given the router's role in broadband access and local network management, exploitation could impact both corporate networks and critical infrastructure sectors relying on stable internet connectivity. The risk is heightened in environments where network segmentation is weak or where monitoring of network traffic is insufficient. Additionally, the lack of encryption in credential transmission violates best practices and regulatory requirements such as GDPR, which mandates protection of personal data in transit. Organizations may face compliance issues and reputational damage if exploited. The absence of a patch means organizations must rely on mitigation strategies until a vendor fix is available.

1. Immediate network-level mitigations should include segmenting management interfaces onto isolated VLANs inaccessible from general user networks to reduce exposure. 2. Deploy network monitoring and intrusion detection systems capable of detecting unusual access patterns or credential sniffing attempts. 3. Use VPNs or secure tunnels for accessing router management interfaces to ensure encryption of credentials in transit. 4. Disable remote management interfaces if not required or restrict access to trusted IP addresses only. 5. Regularly audit router configurations and logs for unauthorized access attempts. 6. Educate network administrators about the risks of using unencrypted management interfaces and enforce strong password policies. 7. Engage with Digisol for firmware updates or patches and plan for timely deployment once available. 8. Consider replacing affected devices with models that support secure management protocols such as HTTPS with strong TLS configurations. 9. Implement network segmentation and zero-trust principles to limit the impact of a compromised device.