CVE-2025-7419 is a critical stack-based buffer overflow vulnerability identified in the Tenda O3V2 device, specifically version 1.0.0.12(3880). The flaw exists in the httpd component within the function fromSpeedTestSet, located in the /goform/setRateTest endpoint. The vulnerability arises due to improper handling of the 'destIP' 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, increasing the risk profile significantly. The CVSS v4.0 score is 8.7 (high severity), reflecting the ease of exploitation (network attack vector, low complexity), no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently observed in the wild, the public disclosure of the exploit code increases the likelihood of exploitation attempts. The Tenda O3V2 is typically used as a wireless access point or network extender, often deployed in small to medium enterprise or home office environments. The vulnerability could allow attackers to gain control over the device, intercept or manipulate network traffic, or disrupt network connectivity.

For European organizations, this vulnerability poses a significant risk, especially for those relying on Tenda O3V2 devices in their network infrastructure. Successful exploitation could lead to full compromise of the affected device, enabling attackers to pivot into internal networks, intercept sensitive data, or disrupt critical services. Given the device's role in network connectivity, availability impacts could affect business operations, particularly in SMEs and remote office setups where such devices are common. Confidentiality breaches could expose internal communications or credentials, while integrity compromises could allow attackers to alter network configurations or inject malicious traffic. The remote and unauthenticated nature of the exploit increases the threat surface, making it a viable vector for widespread attacks or targeted intrusions. Additionally, the lack of a patch at the time of disclosure means organizations must rely on mitigations to reduce exposure.

1. Immediate network segmentation: Isolate Tenda O3V2 devices from critical network segments to limit potential lateral movement. 2. Access control: Restrict management interface access to trusted IP addresses only, using firewall rules or VLAN segmentation. 3. Disable or restrict the vulnerable endpoint (/goform/setRateTest) if possible, through device configuration or network-level blocking. 4. Monitor network traffic for unusual requests targeting the /goform/setRateTest endpoint or anomalous behavior indicative of exploitation attempts. 5. Implement intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics for buffer overflow attempts against Tenda devices. 6. Engage with Tenda support or vendor channels to obtain firmware updates or patches as soon as they become available. 7. Plan for device replacement if patches are not forthcoming, prioritizing devices in sensitive or high-risk environments. 8. Educate network administrators about the vulnerability and ensure incident response plans include steps for this specific threat.