CVE-2025-34048 is a path traversal vulnerability classified under CWE-22, discovered in the web management interface of D-Link DSL-2730U, DSL-2750U, and DSL-2750E ADSL routers running firmware versions IN_1.02, SEA_1.04, and SEA_1.07. The vulnerability stems from inadequate input validation on the 'getpage' parameter within the /cgi-bin/webproc CGI script, which is accessible without authentication. By crafting malicious HTTP requests that manipulate this parameter, an attacker can traverse the filesystem hierarchy beyond the intended restricted directory, enabling arbitrary file reads on the device. This can expose sensitive information such as configuration files, credentials, or other internal data stored on the router. The vulnerability has a CVSS 4.0 base score of 8.7, reflecting its high severity due to network attack vector, no required privileges or user interaction, and a high impact on confidentiality. While no public exploit code has been released, the Shadowserver Foundation observed exploitation attempts in February 2025, indicating active reconnaissance or targeted attacks. The flaw affects multiple firmware versions primarily deployed in certain regional markets, and the lack of authentication makes it particularly dangerous for devices exposed to untrusted networks. The vulnerability does not impact integrity or availability directly but poses a significant risk of information disclosure that could facilitate further attacks or compromise of network infrastructure.

For European organizations, the exploitation of CVE-2025-34048 could lead to unauthorized disclosure of sensitive router configuration data, including administrative credentials and network topology information. This exposure can facilitate lateral movement within corporate networks, enable persistent access, or allow attackers to manipulate network traffic by compromising the router. Organizations relying on affected D-Link models for internet connectivity or internal network routing are at risk, especially if remote management interfaces are accessible from untrusted networks. The confidentiality breach could also impact compliance with data protection regulations such as GDPR if personal or sensitive data is indirectly exposed through compromised network devices. Additionally, critical infrastructure operators using these routers may face increased risk of espionage or sabotage. The lack of authentication and ease of exploitation heighten the threat level, making timely mitigation essential to prevent potential data breaches or operational disruptions.

1. Immediately restrict remote access to the router’s web management interface by disabling WAN-side management or limiting access to trusted IP addresses only. 2. Check with D-Link for firmware updates or patches addressing this vulnerability and apply them promptly once available. 3. If no patch is available, consider replacing affected devices with models confirmed to be secure. 4. Implement network segmentation to isolate vulnerable routers from critical systems and sensitive data. 5. Deploy intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious HTTP requests targeting /cgi-bin/webproc or unusual path traversal patterns. 6. Regularly audit router configurations and logs for signs of unauthorized access or exploitation attempts. 7. Educate IT staff on the risks of exposing management interfaces and enforce strong access controls. 8. Use VPNs or secure tunnels for remote management to reduce exposure. 9. Maintain an inventory of network devices to identify and prioritize vulnerable routers for remediation. 10. Coordinate with internet service providers if routers are ISP-supplied to ensure timely updates and support.