CVE-2025-11423 is a critical security vulnerability identified in Tenda CH22 routers running firmware version 1.0.0.1. The vulnerability resides in the formSafeEmailFilter function located in the /goform/SafeEmailFilter endpoint. Specifically, the issue arises from improper handling of the 'page' argument, which can be manipulated remotely by an attacker to cause memory corruption. This memory corruption can lead to undefined behavior, including potential remote code execution or denial of service conditions. The vulnerability is exploitable over the network without any authentication or user interaction, making it highly accessible to attackers. The CVSS 4.0 score of 9.3 reflects the critical nature of this flaw, with high impact on confidentiality, integrity, and availability, and ease of exploitation. Although no confirmed exploits are currently observed in the wild, a public proof-of-concept exploit exists, increasing the likelihood of active exploitation. The vulnerability affects only the specific firmware version 1.0.0.1 of the Tenda CH22 product, which is a consumer and small business router commonly deployed in various regions. The lack of an official patch at the time of disclosure further elevates the risk. Attackers exploiting this vulnerability could gain unauthorized control over the device, intercept or manipulate network traffic, or disrupt network services.

The impact of CVE-2025-11423 on organizations worldwide can be severe. Successful exploitation allows remote attackers to corrupt memory on Tenda CH22 routers, potentially leading to remote code execution or denial of service. This can compromise the confidentiality and integrity of network traffic passing through the device, enabling interception, manipulation, or redirection of sensitive data. Additionally, attackers could disrupt network availability by crashing or destabilizing the router, causing downtime and operational disruption. For organizations relying on Tenda CH22 routers in their network infrastructure, this vulnerability poses a direct threat to network security and business continuity. The ease of exploitation without authentication or user interaction increases the risk of widespread attacks, especially in environments with exposed management interfaces. The public availability of an exploit further raises the likelihood of targeted attacks or automated scanning campaigns. Compromise of these routers could also serve as a foothold for lateral movement within corporate networks or as part of larger botnet operations. Overall, the vulnerability threatens critical network infrastructure and the security posture of affected organizations.

To mitigate CVE-2025-11423, organizations should first verify if they are using Tenda CH22 routers running firmware version 1.0.0.1 and immediately restrict access to the /goform/SafeEmailFilter endpoint. Network administrators should implement access control lists (ACLs) or firewall rules to limit management interface exposure to trusted internal networks only, blocking all external access. Network segmentation should be employed to isolate vulnerable devices from critical assets. Monitoring and logging should be enhanced to detect unusual requests targeting the 'page' parameter or attempts to exploit the vulnerability. If possible, disable or restrict the formSafeEmailFilter functionality until a vendor patch is available. Organizations should maintain close communication with Tenda for firmware updates and apply patches as soon as they are released. In the absence of an official patch, consider deploying intrusion prevention systems (IPS) with custom signatures to detect exploit attempts. Regularly update network device firmware and conduct vulnerability assessments to identify and remediate similar risks proactively. Finally, educate IT staff about this vulnerability and ensure incident response plans include procedures for handling exploitation attempts against network infrastructure devices.