CVE-2025-12942 is a vulnerability classified under CWE-20 (Improper Input Validation) found in NETGEAR R6260 and R6850 routers running firmware versions through 1.1.0.86. The flaw allows unauthenticated attackers connected to the local area network (LAN) who can perform man-in-the-middle (MiTM) attacks and gain control over the DNS server functionality of the device to execute arbitrary commands on the router. The root cause is insufficient validation of input data, which enables attackers to inject malicious commands via manipulated DNS requests or other network traffic intercepted or relayed through MiTM techniques. Exploitation does not require user interaction but does require the attacker to have LAN access and some level of privilege (low privileges per CVSS). The vulnerability impacts confidentiality, integrity, and availability by allowing attackers to redirect DNS queries, intercept or modify network traffic, and execute commands that could compromise the router or the internal network. The CVSS 4.8 score reflects medium severity due to the requirement for LAN access and higher attack complexity. No public exploits or patches are currently available, increasing the importance of proactive mitigation. The vulnerability affects devices widely used in home and small office environments, which may be part of larger organizational networks or remote sites.

For European organizations, this vulnerability poses a risk primarily to network infrastructure security, especially in environments where NETGEAR R6260 and R6850 routers are deployed. Successful exploitation could lead to DNS hijacking, allowing attackers to redirect users to malicious sites, intercept sensitive communications, or disrupt network services. Command execution on the router could enable attackers to alter configurations, disable security features, or pivot to other internal systems, potentially leading to data breaches or service outages. Organizations with remote offices or home workers using these routers are particularly vulnerable due to the LAN access requirement. The impact on confidentiality, integrity, and availability could be significant if exploited in critical infrastructure sectors such as finance, healthcare, or government. The medium CVSS score suggests moderate risk, but the potential for lateral movement and persistent compromise elevates concern for targeted attacks within Europe.

1. Immediately segment networks to restrict LAN access only to trusted devices and users, minimizing exposure to potential attackers. 2. Implement strict network access controls and monitoring for unusual DNS traffic or MiTM activity within local networks. 3. Disable or restrict DNS server functionality on affected routers if possible, or replace with dedicated DNS infrastructure. 4. Enforce strong authentication and authorization policies on network devices to limit privilege escalation. 5. Monitor router logs and network traffic for signs of command injection or configuration changes. 6. Educate users and administrators about the risks of connecting untrusted devices to LANs where these routers are deployed. 7. Apply firmware updates or patches from NETGEAR as soon as they become available. 8. Consider replacing vulnerable devices with models that have no known input validation issues if patching is delayed.