The vulnerability identified as CVE-2025-46413 affects BUFFALO INC.'s WSR-1800AX4 series Wi-Fi routers running firmware versions prior to 1.09. The root cause is the use of password hashes with insufficient computational effort in the router's implementation of Wi-Fi Protected Setup (WPS). WPS is a feature designed to simplify the connection process by using a PIN code or push-button method. However, in this case, the insufficient computational effort in hashing allows an attacker to perform an offline or online brute-force attack more efficiently against the WPS PIN or Wi-Fi password. This weakness can lead to the disclosure of the WPS PIN and/or Wi-Fi password without requiring any authentication or user interaction, provided the attacker has network access to the device. The vulnerability primarily compromises confidentiality, as an attacker gaining access to the Wi-Fi credentials could intercept network traffic or gain unauthorized network access. The CVSS v3.0 score is 4.3, reflecting a medium severity with attack vector as adjacent network, low attack complexity, no privileges required, no user interaction, and limited impact on confidentiality only. No known exploits have been reported in the wild, but the vulnerability poses a risk especially in environments where WPS is enabled and firmware is outdated. The issue can be remediated by updating the router firmware to version 1.09 or later, which presumably strengthens the password hashing mechanism or disables vulnerable WPS functionality.

For European organizations, this vulnerability could lead to unauthorized access to internal networks via compromised Wi-Fi credentials, potentially exposing sensitive data and internal systems to attackers. While the vulnerability does not directly impact system integrity or availability, the confidentiality breach could facilitate further lateral movement or data exfiltration. Organizations relying on BUFFALO WSR-1800AX4 routers in office or industrial environments may face increased risk, especially if WPS is enabled and firmware is not updated. The risk is heightened in sectors with sensitive information or critical infrastructure, such as finance, healthcare, and manufacturing. Additionally, compromised Wi-Fi access could be used as a foothold for more sophisticated attacks. However, the requirement for network adjacency and the absence of known exploits reduce the immediate threat level. Overall, the vulnerability represents a moderate risk that should be addressed promptly to prevent potential exploitation.

1. Immediately update all BUFFALO WSR-1800AX4 routers to firmware version 1.09 or later to apply the security fix addressing the weak password hashing. 2. Disable WPS functionality entirely if it is not required, as WPS has historically been a common attack vector. 3. For environments where WPS must remain enabled, monitor network traffic for unusual authentication attempts or brute-force activity targeting the router. 4. Implement network segmentation to isolate Wi-Fi networks from sensitive internal systems, minimizing the impact of potential credential compromise. 5. Enforce strong Wi-Fi password policies and consider using WPA3 where supported to enhance wireless security. 6. Conduct regular security audits and vulnerability assessments on network infrastructure devices to detect outdated firmware or insecure configurations. 7. Educate IT staff and users about the risks associated with WPS and the importance of timely patching.