The vulnerability identified as CVE-2025-63456 affects the Tenda AX-1803 router firmware version 1.0.0.1. It is a stack-based buffer overflow occurring in the SetSysTimeCfg function when processing the time parameter. This flaw allows an attacker to send a specially crafted request to the router's management interface, causing the device to crash or reboot, resulting in a Denial of Service (DoS) condition. The vulnerability does not require any authentication or user interaction, making it remotely exploitable by any attacker with network access to the device. The CVSS 3.1 vector (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) indicates that the attack can be performed over the network with low attack complexity, no privileges or user interaction needed, and impacts only availability. No confidentiality or integrity impacts are reported. The underlying weakness is a classic stack overflow (CWE-121), which can lead to memory corruption and process crashes. Although no public exploits or patches are currently available, the vulnerability poses a risk to network stability, especially in environments relying on these routers for critical connectivity. The lack of patches necessitates interim mitigations to reduce exposure until vendor updates are released.

For European organizations, this vulnerability could lead to network outages or intermittent connectivity loss if attackers exploit the flaw to crash routers. This can disrupt business operations, especially for small and medium enterprises or branch offices relying on Tenda AX-1803 devices for internet access or internal network routing. Critical services dependent on continuous network availability may experience downtime, affecting productivity and potentially leading to financial losses. While the vulnerability does not expose sensitive data or allow unauthorized data modification, the availability impact can indirectly affect confidentiality and integrity by interrupting security monitoring or incident response capabilities. The absence of known exploits reduces immediate risk, but the ease of exploitation and lack of authentication requirements mean attackers could weaponize this vulnerability in targeted or opportunistic attacks. European organizations with limited IT resources may find recovery challenging without vendor support or patches.

1. Immediately disable remote management interfaces on Tenda AX-1803 routers to prevent external exploitation. 2. Restrict network access to router management ports using firewall rules or network segmentation, allowing only trusted internal IP addresses. 3. Monitor network traffic for unusual or malformed requests targeting the SetSysTimeCfg function or time configuration endpoints. 4. Implement network anomaly detection systems to alert on potential DoS attempts against router infrastructure. 5. Maintain up-to-date inventories of network devices to identify affected models and firmware versions. 6. Engage with Tenda support channels to obtain patches or firmware updates as soon as they become available. 7. Consider temporary replacement or isolation of vulnerable devices in critical network segments until patched. 8. Educate IT staff on recognizing symptoms of router crashes or reboots that may indicate exploitation attempts. 9. Regularly back up router configurations to enable rapid recovery post-incident. 10. Review and enhance incident response plans to include scenarios involving network device DoS attacks.