CVE-2025-9806 is a vulnerability identified in the Tenda F1202 router firmware versions 1.2.0.9, 1.2.0.14, and 1.2.0.20. The flaw resides in an unspecified function related to the administrative interface, specifically involving the file /etc_ro/shadow. The vulnerability manifests as hard-coded credentials embedded within the device's firmware, which can be triggered through manipulation of an input named 'Fireitup'. This issue allows an attacker with local access to the device to potentially authenticate using these hard-coded credentials. However, exploitation is constrained by several factors: the attack requires local access to the device, a high degree of complexity, and elevated privileges (high privileges are required to execute the attack). There is no need for user interaction, and the vulnerability does not affect confidentiality, integrity, or availability beyond the limited scope of local administrative access. The CVSS 4.0 base score is 1.8, indicating a low severity level. The exploitability is considered difficult, and no known exploits are currently observed in the wild. The vulnerability was publicly disclosed on September 2, 2025, but no patches or mitigations have been linked yet. The presence of hard-coded credentials in a network device's administrative interface is a security concern as it can allow unauthorized local users to gain administrative access, potentially leading to configuration changes or further compromise if combined with other vulnerabilities or access vectors. However, the requirement for local access and high complexity significantly limits the practical risk.

For European organizations, the direct impact of CVE-2025-9806 is relatively limited due to the low severity and the constraints on exploitation. The vulnerability requires local access to the device and high privileges, which reduces the likelihood of remote or large-scale exploitation. However, in environments where physical or local network access to Tenda F1202 routers is possible—such as branch offices, small business locations, or less secure network segments—an attacker with insider access or who has compromised a local machine could leverage this vulnerability to gain administrative control over the router. This could lead to unauthorized configuration changes, interception or redirection of network traffic, or establishing persistence within the network. Given that routers are critical infrastructure components, any unauthorized administrative access can have cascading effects on network security and availability. European organizations using Tenda F1202 devices should be aware of this risk, especially in scenarios where physical security is weaker or where local network segmentation is insufficient. The low CVSS score and difficulty of exploitation mean that this vulnerability is unlikely to be a primary attack vector but could be leveraged in multi-stage attacks or insider threat scenarios.

1. Physical and Network Access Controls: Restrict physical access to Tenda F1202 devices and ensure that local network segments containing these routers are secured and segmented to limit unauthorized local access. 2. Firmware Updates and Vendor Communication: Although no patches are currently linked, organizations should monitor Tenda's official channels for firmware updates addressing this vulnerability and apply them promptly once available. 3. Device Replacement or Hardening: Consider replacing affected Tenda F1202 devices with models that do not have known hard-coded credential issues or that support stronger authentication mechanisms. 4. Administrative Access Monitoring: Implement logging and monitoring of administrative access attempts on these routers to detect unusual or unauthorized access patterns. 5. Network Segmentation: Isolate management interfaces from general user networks to reduce the risk of local exploitation. 6. Incident Response Preparedness: Prepare to respond to potential insider threats or local attacks by having clear procedures for investigating suspicious router access or configuration changes. 7. Vendor Engagement: Engage with Tenda support to request information on mitigation plans or interim workarounds such as disabling vulnerable interfaces or changing default credentials if possible.