CVE-2025-11666 is a vulnerability discovered in the Tenda RP3 Pro router series, specifically affecting firmware versions up to 22.5.7.93. The flaw resides in the force_upgrade.sh script, part of the Firmware Update Handler component, where a hard-coded password is used. An attacker with local access and high privileges can manipulate the argument current_force_upgrade_pwd to bypass authentication mechanisms relying on this password. This hard-coded credential effectively allows unauthorized firmware upgrade or other privileged operations, compromising the device's security. The vulnerability does not require network access or user interaction but does require local execution privileges, which limits remote exploitation but still poses a significant risk in environments where local access is possible. The CVSS 4.0 base score of 8.4 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no need for user interaction. Although no exploits are currently observed in the wild, the publication of proof-of-concept code increases the risk of exploitation. The vulnerability could allow attackers to install malicious firmware, disrupt network operations, or gain persistent control over the device, potentially serving as a foothold for lateral movement within organizational networks.

For European organizations, the impact of CVE-2025-11666 can be substantial. Tenda RP3 Pro routers are often used in small to medium business and home office environments, which may serve as gateways to corporate networks. Exploitation could lead to unauthorized firmware installation, enabling attackers to intercept, modify, or disrupt network traffic, steal sensitive data, or launch further attacks against internal systems. The compromise of network infrastructure devices undermines trust in network security and can lead to significant operational disruptions. In sectors such as finance, healthcare, and critical infrastructure, where data confidentiality and availability are paramount, this vulnerability could facilitate espionage, data breaches, or denial of service. The requirement for local access somewhat limits the attack surface but does not eliminate risk, especially in environments with shared physical access or insufficient network segmentation. Additionally, the availability of exploit code increases the likelihood of targeted attacks or insider threats leveraging this vulnerability.

To mitigate CVE-2025-11666, organizations should first monitor Tenda's official channels for firmware updates addressing this issue and apply patches promptly once available. Until patches are released, restrict physical and local network access to Tenda RP3 Pro devices by implementing strict access controls, including network segmentation and limiting administrative privileges. Disable or restrict the use of the firmware update handler if possible, or monitor its usage for suspicious activity. Employ network monitoring to detect anomalous behavior indicative of firmware manipulation attempts. Consider replacing affected devices with models from vendors with stronger security track records if patching is delayed. Additionally, enforce strong internal policies to prevent unauthorized local access to network devices and educate staff about the risks of local exploitation. Regularly audit device configurations and logs to identify potential exploitation attempts early.