CVE-2025-63456 identifies a stack overflow vulnerability in the Tenda AX-1803 router firmware version 1.0.0.1, specifically within the SetSysTimeCfg function that processes the time parameter. A stack overflow occurs when more data is written to a buffer located on the stack than it can hold, potentially overwriting adjacent memory and causing unpredictable behavior. In this case, an attacker can send a specially crafted request with a malformed time parameter to trigger the overflow. The primary consequence is a Denial of Service (DoS), where the router may crash, reboot, or become unresponsive, disrupting network connectivity. The vulnerability does not require authentication or user interaction, making remote exploitation feasible if the management interface is exposed. No patches or fixes have been published yet, and no exploits are known to be active in the wild. The lack of a CVSS score limits precise severity quantification, but the nature of the vulnerability suggests a moderate risk focused on availability impact. The affected device is commonly used in consumer and small business environments, which may lack robust security controls, increasing exposure risk. This vulnerability highlights the importance of secure firmware development and timely patching in network infrastructure devices.

For European organizations, the primary impact of CVE-2025-63456 is the potential disruption of network services due to router crashes or reboots caused by the DoS condition. This can affect business continuity, especially for small and medium enterprises (SMEs) relying on Tenda AX-1803 routers for internet connectivity and internal networking. The vulnerability could be exploited remotely if the router’s management interface is accessible from untrusted networks, leading to potential downtime and productivity loss. While it does not directly compromise confidentiality or integrity, the availability impact can cascade, affecting critical business operations and possibly delaying communications or transactions. Organizations with limited IT resources may find recovery and mitigation more challenging. Additionally, if attackers combine this DoS vulnerability with other attack vectors, it could facilitate further exploitation or lateral movement within networks. The threat is more pronounced in sectors with high reliance on stable network infrastructure, such as finance, healthcare, and public services. Overall, the vulnerability poses a moderate operational risk that requires attention to prevent service interruptions.

1. Monitor Tenda’s official channels for firmware updates addressing this vulnerability and apply patches promptly once available. 2. Restrict access to the router’s management interface by disabling remote management or limiting it to trusted IP addresses only. 3. Implement network segmentation to isolate critical systems from devices that may be vulnerable, reducing the blast radius of a potential DoS attack. 4. Employ firewall rules to block unauthorized or suspicious traffic targeting router management ports. 5. Regularly audit network devices for outdated firmware and replace unsupported hardware where feasible. 6. Educate IT staff and users about the risks of exposing network devices to the internet and enforce strong network security policies. 7. Consider deploying intrusion detection/prevention systems (IDS/IPS) to identify and block malformed packets attempting to exploit this vulnerability. 8. Maintain robust backup and recovery procedures to quickly restore network functionality in case of disruption.