CVE-2025-7853 is a critical stack-based buffer overflow vulnerability identified in the Tenda FH451 router, specifically affecting version 1.0.0.9. The flaw exists in the function fromSetIpBind within the /goform/SetIpBind endpoint. The vulnerability arises due to improper handling of the 'page' argument, which can be manipulated by an attacker to overflow the stack buffer. This overflow can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable without requiring user interaction or authentication, making it highly dangerous. The CVSS 4.0 score of 8.7 reflects a high severity level, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), and no user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability (all rated high), indicating that successful exploitation could compromise sensitive data, alter device behavior, or disrupt network services. Although no public exploit is currently known to be actively used in the wild, the disclosure of the exploit code increases the risk of imminent attacks. The absence of available patches or mitigation links at this time further exacerbates the threat, emphasizing the urgency for affected organizations to implement protective measures. Given the critical role routers play in network infrastructure, exploitation could allow attackers to pivot into internal networks, intercept or manipulate traffic, or disrupt connectivity.

For European organizations, the impact of CVE-2025-7853 could be significant. The Tenda FH451 router is commonly used in small to medium-sized enterprises and residential environments, which means that both corporate and home networks could be vulnerable. Exploitation could lead to unauthorized access to internal networks, data breaches, and disruption of business operations due to network outages. The ability to execute arbitrary code remotely without authentication increases the risk of widespread compromise, potentially enabling attackers to deploy malware, establish persistent backdoors, or launch further attacks within the network. Critical sectors such as finance, healthcare, and government agencies relying on vulnerable devices could face operational disruptions and data confidentiality breaches. Additionally, the disruption of network availability could impact remote work capabilities, which remain vital in the European context. The lack of patches means organizations must rely on network-level defenses and configuration changes to mitigate risk, which may not be sufficient against sophisticated attackers.

Given the absence of official patches, European organizations should take immediate and specific steps to mitigate the risk posed by CVE-2025-7853. First, identify and inventory all Tenda FH451 devices running version 1.0.0.9 within the network. Where possible, isolate these devices from direct exposure to the internet by placing them behind additional firewalls or VPNs. Disable or restrict access to the /goform/SetIpBind endpoint if feasible, using router configuration settings or network-level filtering. Implement strict network segmentation to limit lateral movement if a device is compromised. Monitor network traffic for unusual activity targeting the vulnerable endpoint, employing intrusion detection systems with updated signatures. Consider replacing vulnerable devices with models from vendors that provide timely security updates. Additionally, enforce strong network access controls and ensure that router management interfaces are not accessible from untrusted networks. Regularly review vendor communications for patch releases and apply updates promptly once available.