CVE-2025-63455 is a stack overflow vulnerability identified in the Tenda AX-3 router firmware version 16.03.12.10_CN. The vulnerability arises from improper handling of the shareSpeed parameter within the fromSetWifiGusetBasic function. Specifically, the function does not adequately validate or limit input size, allowing an attacker to craft a malicious request that overflows the stack memory. This overflow can cause the device to crash or reboot unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability can be exploited remotely over the network without requiring any authentication or user interaction, making it particularly dangerous for exposed devices. The Common Weakness Enumeration (CWE) classification is CWE-121, indicating a classic stack-based buffer overflow. The CVSS v3.1 base score is 7.5, reflecting a high severity due to network attack vector, low attack complexity, no privileges required, and no user interaction needed. Currently, there are no known exploits in the wild and no official patches have been published. The vulnerability affects the availability of the device but does not compromise confidentiality or integrity. This flaw could be leveraged by attackers to disrupt network connectivity for users relying on the Tenda AX-3 router, potentially impacting business operations or critical services dependent on stable internet access.

For European organizations, the primary impact of CVE-2025-63455 is the disruption of network availability caused by forced router crashes or reboots. This can lead to loss of internet connectivity, interruption of business-critical applications, and degraded productivity. Organizations using Tenda AX-3 routers in their network infrastructure, especially in small office/home office (SOHO) environments or branch offices, may experience localized outages. Critical sectors such as healthcare, finance, and public administration could face operational risks if these devices are part of their network perimeter or internal connectivity. Additionally, denial of service conditions could be exploited as part of larger multi-vector attacks or to create distractions while other attacks are carried out. The lack of authentication and user interaction requirements increases the risk of automated exploitation attempts, especially if devices are exposed to the internet or poorly segmented networks. However, the absence of known exploits in the wild and the current lack of patches somewhat mitigate immediate widespread impact.

To mitigate CVE-2025-63455, European organizations should first identify any Tenda AX-3 routers running firmware version 16.03.12.10_CN within their networks. Since no official patches are currently available, organizations should implement compensating controls: 1) Disable remote management interfaces and restrict administrative access to trusted internal networks only. 2) Segment networks to isolate vulnerable devices from critical infrastructure and sensitive data. 3) Employ network intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious traffic targeting the shareSpeed parameter or related router functions. 4) Limit exposure by blocking unsolicited inbound traffic to router management ports at the perimeter firewall. 5) Regularly audit router configurations and firmware versions to prepare for timely patch deployment once available. 6) Engage with Tenda support channels to obtain updates or workarounds. 7) Educate IT staff about the vulnerability to recognize signs of exploitation such as unexpected router reboots or connectivity loss. These targeted actions go beyond generic advice by focusing on network architecture adjustments and proactive monitoring tailored to this specific vulnerability.