CVE-2025-5495 is a vulnerability identified in the Netgear WNR614 router, specifically version 1.1.0.28_1.0.1WW. The flaw resides in the URL Handler component of the device's firmware, where improper handling of a crafted input string containing the null byte sequence "%00currentsetting.htm" leads to improper authentication bypass. This vulnerability allows an unauthenticated remote attacker to access restricted functionality or sensitive configuration pages without valid credentials. The issue is exploitable remotely over the network without requiring any user interaction or prior authentication, increasing the attack surface significantly. Although the exact internal mechanism is not fully detailed, the presence of the null byte (%00) suggests a classic null byte injection or truncation attack that bypasses authentication checks by manipulating URL parsing or access control logic. The vulnerability has been publicly disclosed and was circulating as a zero-day since early 2024, indicating that threat actors may have had extended opportunity to develop exploits. The CVSS v4.0 base score is 6.9, categorized as medium severity, reflecting the network attack vector, no required privileges or user interaction, but limited impact on confidentiality, integrity, and availability (each rated low). No official patches or mitigations have been linked yet, and no known exploits in the wild have been confirmed at the time of publication. This vulnerability could allow attackers to gain unauthorized access to router settings, potentially leading to further compromise such as network traffic interception, device configuration changes, or pivoting attacks within the affected network environment.

For European organizations, the impact of CVE-2025-5495 can be significant, especially for small and medium enterprises (SMEs) and home office environments relying on Netgear WNR614 routers for internet connectivity and network management. Unauthorized access to router configuration can lead to exposure of internal network topology, interception or redirection of network traffic, insertion of malicious DNS entries, or disabling security features such as firewalls. This could facilitate further attacks like data exfiltration, lateral movement, or deployment of malware within corporate networks. Critical infrastructure or organizations with remote sites using this router model may face operational disruptions or data breaches. Given the remote exploitability without authentication, attackers can target vulnerable devices en masse, increasing risk of widespread compromise. The medium severity rating suggests that while the vulnerability is serious, it may not directly allow full system takeover or data destruction but serves as a stepping stone for more advanced attacks. European organizations with limited IT security resources or delayed patch management processes are particularly vulnerable to exploitation.

To mitigate CVE-2025-5495, European organizations should take immediate and specific actions: 1) Identify all Netgear WNR614 devices running the affected firmware version (1.1.0.28_1.0.1WW) through asset inventories and network scans. 2) Restrict remote management access to these devices by disabling WAN-side administration interfaces or limiting access via firewall rules to trusted IP addresses only. 3) Implement network segmentation to isolate vulnerable routers from critical internal systems and sensitive data. 4) Monitor network traffic for unusual access patterns or attempts to access URLs containing null byte sequences or "currentsetting.htm". 5) Contact Netgear support or check official channels regularly for firmware updates or patches addressing this vulnerability and apply them promptly once available. 6) As a temporary workaround, consider replacing affected devices with models not impacted by this vulnerability if patching is delayed. 7) Educate IT staff about this vulnerability and ensure incident response plans include steps for detecting and responding to exploitation attempts. These targeted measures go beyond generic advice by focusing on access control, monitoring, and asset management specific to this vulnerability and device.