CVE-2025-7807 is a critical stack-based buffer overflow vulnerability identified in the Tenda FH451 router, specifically version 1.0.0.9. The flaw exists in the function fromSafeUrlFilter within the /goform/SafeUrlFilter endpoint. This vulnerability arises due to improper handling and validation of the 'Go/page' argument, which can be manipulated by an attacker to overflow the stack buffer. Exploiting this vulnerability could allow a remote attacker to execute arbitrary code on the device without requiring user interaction or prior authentication. The vulnerability is remotely exploitable over the network, making it a significant threat to affected devices. The CVSS 4.0 base score is 8.7, indicating a high severity level, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). Although no public exploits are currently known to be in the wild, the disclosure of the exploit details increases the risk of exploitation. The vulnerability can lead to complete compromise of the router, allowing attackers to manipulate network traffic, intercept sensitive data, or use the device as a foothold for further attacks within the network.

For European organizations, the impact of this vulnerability can be substantial. Tenda routers like the FH451 are commonly used in small to medium-sized enterprises and home office environments, which are integral parts of the broader organizational network infrastructure. A successful exploit could lead to unauthorized access to internal networks, data exfiltration, disruption of network services, and potential lateral movement to more critical systems. Given the critical nature of the vulnerability and the router's role as a network gateway, exploitation could compromise confidentiality, integrity, and availability of organizational data and services. This is particularly concerning for sectors with stringent data protection requirements under GDPR, where breaches could lead to regulatory penalties and reputational damage. Additionally, the ability to remotely exploit the vulnerability without authentication or user interaction increases the risk of automated attacks and widespread compromise.

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Immediate firmware upgrade: Check for and apply any official patches or firmware updates released by Tenda addressing CVE-2025-7807. If no patch is available, consider temporarily disabling or restricting access to the vulnerable /goform/SafeUrlFilter endpoint via firewall rules or access control lists. 2) Network segmentation: Isolate vulnerable Tenda FH451 devices from critical network segments to limit potential lateral movement in case of compromise. 3) Monitor network traffic: Deploy intrusion detection/prevention systems (IDS/IPS) to detect anomalous requests targeting the /goform/SafeUrlFilter endpoint or unusual traffic patterns indicative of exploitation attempts. 4) Replace vulnerable devices: For high-risk environments, consider replacing affected Tenda FH451 routers with devices from vendors with a stronger security track record and timely patch management. 5) Implement strict network access controls: Limit remote management interfaces exposure to the internet and enforce strong authentication mechanisms where possible. 6) Conduct regular vulnerability assessments and penetration tests focusing on network infrastructure devices to identify and remediate similar issues proactively.