CVE-2025-63458 is a stack-based buffer overflow vulnerability identified in the Tenda AX-1803 router firmware version 1.0.0.1. The vulnerability arises from improper handling of the timeZone parameter within the form_fast_setting_wifi_set function. When a specially crafted request is sent to this function, it causes a stack overflow, leading to a denial of service (DoS) condition by crashing or destabilizing the router's firmware. The vulnerability is remotely exploitable without requiring any authentication or user interaction, increasing its risk profile. The CVSS v3.1 base score of 7.5 reflects a high severity, primarily due to the network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact is limited to availability (A:H) with no confidentiality or integrity loss. Although no public exploits have been reported yet, the vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), a common and well-understood weakness that attackers can leverage to disrupt network operations. The lack of an official patch at the time of disclosure necessitates proactive mitigation steps to prevent exploitation. Given the widespread use of Tenda routers in small to medium enterprises and home networks, this vulnerability poses a tangible risk to network stability.

For European organizations, exploitation of CVE-2025-63458 could result in denial of service conditions on affected Tenda AX-1803 routers, causing network outages and loss of internet connectivity. This disruption can affect business continuity, especially for organizations relying on these routers for critical communications or remote access. The absence of confidentiality or integrity impact limits data breach risks but does not diminish the operational impact. Sectors such as small businesses, educational institutions, and remote offices that commonly deploy consumer-grade routers may be particularly vulnerable. Additionally, disruption in network availability could indirectly affect services dependent on stable internet connections, including VoIP, cloud applications, and remote work infrastructure. The lack of known exploits in the wild currently reduces immediate risk, but the ease of exploitation and public disclosure may prompt attackers to develop exploits rapidly. European organizations should consider the potential for targeted attacks aiming to disrupt operations or cause reputational damage.

1. Monitor Tenda’s official channels for firmware updates addressing CVE-2025-63458 and apply patches promptly once released. 2. Until patches are available, restrict access to the router’s management interface by implementing network segmentation and firewall rules to limit exposure to untrusted networks. 3. Disable remote management features if not required to reduce the attack surface. 4. Employ network intrusion detection systems (NIDS) to monitor for unusual or malformed requests targeting the timeZone parameter or related router endpoints. 5. Conduct regular network device inventories to identify deployments of Tenda AX-1803 routers and assess their exposure. 6. Educate IT staff about this vulnerability to ensure rapid response and mitigation in case of attempted exploitation. 7. Consider deploying alternative, more secure network equipment in environments where high availability is critical and patching timelines are uncertain.