CVE-2025-51087 is a stack-based buffer overflow vulnerability identified in the Tenda AC8V4 router firmware version V16.03.34.06. The vulnerability occurs in the /goform/saveParentControlInfo endpoint, where improper handling of the 'time' argument allows an attacker to overflow the stack buffer. This type of vulnerability typically arises when input data exceeds the allocated buffer size without proper bounds checking, leading to memory corruption. Exploiting this flaw could enable an attacker to execute arbitrary code with the privileges of the affected process, potentially leading to full device compromise. Since this endpoint relates to parental control settings, it is likely accessible via the router's web interface, which may be exposed on internal networks or, if remote management is enabled, from external networks. No public exploits or patches are currently known, and no CVSS score has been assigned yet. However, the vulnerability's nature suggests a high risk due to the possibility of remote code execution and the critical role of routers in network infrastructure.

For European organizations, the exploitation of this vulnerability could have significant consequences. Routers like the Tenda AC8V4 are often deployed in small to medium business environments and home offices, serving as the primary gateway to the internet. A successful attack could allow threat actors to intercept, manipulate, or redirect network traffic, compromising confidentiality and integrity of communications. Additionally, attackers could use compromised routers as footholds to pivot into internal networks, escalating attacks to critical systems. The disruption or takeover of network infrastructure devices can also impact availability, causing denial of service or degraded network performance. Given the increasing reliance on remote work and interconnected devices, this vulnerability poses a risk to data privacy, regulatory compliance (e.g., GDPR), and operational continuity for European entities.

Organizations should immediately audit their network environments to identify the presence of Tenda AC8V4 routers running the vulnerable firmware version V16.03.34.06. Since no official patch is currently available, mitigation should focus on reducing exposure: disable remote management features on these routers to prevent external access to the vulnerable endpoint; restrict access to the router's web interface to trusted internal IP addresses; implement network segmentation to isolate vulnerable devices from critical assets; monitor network traffic for unusual activity indicative of exploitation attempts; and consider replacing affected devices with models from vendors that provide timely security updates. Additionally, organizations should establish a process to track vendor advisories for forthcoming patches and apply them promptly once released. Employing intrusion detection systems with signatures targeting buffer overflow attempts on router management interfaces can also enhance detection capabilities.