CVE-2025-57064 is a stack overflow vulnerability identified in the Tenda G3 router firmware version 3.0br_V15.11.0.17. The flaw exists in the handling of the bindDhcpIndex parameter within the modifyDhcpRule function. Specifically, the vulnerability arises when a crafted request with a specially malformed bindDhcpIndex parameter is processed, leading to a stack overflow condition. This type of memory corruption can cause the device to crash or reboot unexpectedly, resulting in a Denial of Service (DoS) condition. The vulnerability does not currently have a CVSS score or known exploits in the wild, but the nature of stack overflow vulnerabilities typically allows attackers to disrupt device availability without requiring authentication or user interaction. Since the vulnerability affects the DHCP rule modification functionality, it is likely accessible via the device's management interface, potentially remotely if the interface is exposed. The lack of patch links suggests that no official fix has been released yet. Given that Tenda G3 routers are consumer-grade networking devices, this vulnerability could be exploited by attackers to disrupt network connectivity by causing router outages.

For European organizations, the impact of this vulnerability primarily centers on network availability and operational continuity. Tenda routers are commonly used in small to medium-sized enterprises and residential environments across Europe due to their affordability and ease of use. An attacker exploiting this vulnerability could cause repeated router crashes, leading to intermittent or prolonged network outages. This disruption can affect business operations, remote work capabilities, and access to cloud services. While the vulnerability does not appear to enable data theft or privilege escalation, the resulting DoS can indirectly impact confidentiality and integrity by interrupting security monitoring systems or delaying critical updates. Additionally, organizations relying on Tenda G3 routers in branch offices or home office setups may face increased risk if these devices are accessible from untrusted networks. The absence of known exploits reduces immediate risk, but the vulnerability's presence in widely deployed consumer devices means that opportunistic attackers could weaponize it to cause widespread service interruptions.

To mitigate this vulnerability, European organizations should first identify any Tenda G3 routers running firmware version 3.0br_V15.11.0.17 within their networks. Network asset inventories and device management tools can assist in this discovery. Since no official patch is currently available, organizations should implement compensating controls such as restricting access to the router's management interfaces by limiting them to trusted internal networks and disabling remote management features if enabled. Network segmentation can isolate vulnerable devices from critical infrastructure. Monitoring network traffic for unusual DHCP modification requests may help detect exploitation attempts. Organizations should also engage with Tenda support channels to obtain information on forthcoming patches or firmware updates addressing this issue. Where possible, replacing vulnerable devices with models from vendors with robust security update policies can reduce exposure. Finally, educating users about the risks of exposing home or branch office routers to the internet can prevent exploitation.