CVE-2025-15371 is a vulnerability discovered in several Tenda router models including i24, 4G03 Pro, 4G05, 4G08, G0-8G-PoE, Nova MW5G, and TEG5328F, affecting firmware versions up to 65.10.15.6. The vulnerability arises from hard-coded credentials embedded within a component known as the Shadow File. Specifically, an attacker with local access can manipulate an input parameter named 'Fireitup' to trigger the use of these hard-coded credentials, bypassing normal authentication mechanisms. The attack vector requires local access to the device, and the attacker must have at least low-level privileges (PR:L) but does not require user interaction (UI:N). The CVSS 4.0 base score is 8.5, indicating high severity, with high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). The vulnerability does not require network access (AV:L), meaning remote exploitation is not feasible without prior local access. The exploit has been publicly disclosed, increasing the risk of exploitation, although no confirmed active exploitation in the wild has been reported yet. The presence of hard-coded credentials can allow attackers to escalate privileges, gain persistent access, and potentially control the device, leading to network compromise, data interception, or denial of service. The lack of available patches or firmware updates from the vendor at the time of disclosure complicates mitigation efforts. This vulnerability affects a range of Tenda products commonly used in small to medium business and home environments, which may be integrated into enterprise networks.

For European organizations, this vulnerability poses a significant risk especially in environments where Tenda devices are deployed as primary network gateways or access points. Exploitation could lead to unauthorized administrative access, allowing attackers to intercept sensitive communications, alter network configurations, or disrupt network availability. This is particularly critical for organizations handling sensitive data or operating critical infrastructure. The local access requirement means that attackers must already have some foothold within the network or physical access, which could be achieved through insider threats, compromised internal hosts, or physical proximity. The high impact on confidentiality, integrity, and availability could result in data breaches, operational disruptions, and reputational damage. Additionally, the lack of patches means organizations must rely on compensating controls, increasing operational complexity. The public disclosure of the exploit details raises the likelihood of opportunistic attacks targeting vulnerable Tenda devices across Europe.

1. Immediate network segmentation to isolate Tenda devices from sensitive network segments, limiting local access to trusted personnel and systems only. 2. Implement strict access control policies restricting administrative access to the affected devices, including use of VPNs or jump hosts with multi-factor authentication. 3. Monitor network traffic for unusual activity or unauthorized access attempts to Tenda devices, employing IDS/IPS tuned for router management protocols. 4. Disable or restrict any unnecessary services or interfaces on the affected devices to reduce attack surface. 5. Maintain an asset inventory to identify all affected Tenda models and firmware versions in use. 6. Engage with Tenda support channels to obtain information on forthcoming patches or firmware updates and apply them promptly once available. 7. Consider replacing vulnerable devices with alternative hardware from vendors with robust security track records if patches are delayed. 8. Educate internal staff about the risks of local network access and enforce physical security controls to prevent unauthorized device access. 9. Regularly audit device configurations and credentials to detect unauthorized changes or presence of hard-coded credentials.