CVE-2024-54887 is a buffer overflow vulnerability identified in TP-Link TL-WR940N router models V3 and V4, specifically in firmware versions 3.16.9 and earlier. The vulnerability arises from improper bounds checking of the dnsserver1 and dnsserver2 parameters processed by the /userRpm/Wan6to4TunnelCfgRpm.htm web interface. This interface is accessible to authenticated users, and the flaw allows an attacker with valid credentials to send crafted input that overflows a buffer, enabling arbitrary code execution in the context of the root user. The vulnerability is classified under CWE-120 (Classic Buffer Overflow), which is a common and dangerous software weakness. Exploitation does not require user interaction beyond authentication, and the attack complexity is low due to insufficient access control and input validation. Successful exploitation could allow attackers to fully control the router, modify configurations, intercept or redirect network traffic, or use the device as a foothold for further network attacks. Although no known exploits are publicly available at this time, the high CVSS score (8.0) indicates a significant risk. The vulnerability was reserved in December 2024 and published in January 2025, highlighting its recent discovery. No official patches have been linked yet, emphasizing the need for immediate mitigation steps.

The impact of CVE-2024-54887 is severe for organizations relying on TP-Link TL-WR940N V3 and V4 routers. Exploitation grants root-level control over the device, compromising the confidentiality, integrity, and availability of network traffic passing through the router. Attackers could alter DNS settings to redirect users to malicious sites, intercept sensitive data, or disrupt network connectivity. This could lead to data breaches, man-in-the-middle attacks, and network outages. In enterprise or critical infrastructure environments, compromised routers can serve as entry points for lateral movement and persistent threats. The vulnerability affects the router’s firmware, which is often overlooked in patch management, increasing the risk of exploitation. The requirement for authentication limits the attack surface but does not eliminate risk, as attackers may leverage stolen or default credentials. The absence of known exploits currently provides a window for proactive defense, but the high severity score demands urgent attention.

1. Immediately verify the firmware version of TP-Link TL-WR940N V3 and V4 devices and upgrade to the latest firmware once an official patch is released by TP-Link. 2. Until patches are available, restrict access to the router’s management interface to trusted networks and users only, preferably via VPN or secure management VLANs. 3. Change default credentials and enforce strong, unique passwords to reduce the risk of unauthorized authentication. 4. Disable remote management features if not required to minimize exposure. 5. Monitor router logs and network traffic for unusual activity indicative of exploitation attempts, such as unexpected configuration changes or DNS redirection. 6. Implement network segmentation to isolate vulnerable devices from critical systems. 7. Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting attempts to exploit this vulnerability once available. 8. Educate network administrators about this vulnerability and the importance of timely firmware updates and secure configuration management.