CVE-2025-11418 is a stack-based buffer overflow vulnerability identified in the Tenda CH22 router firmware versions 1.0.0.0 and 1.0.0.1. The vulnerability resides in the HTTP request handler component, specifically within the formWrlsafeset function that processes the /goform/AdvSetWrlsafeset endpoint. The issue arises from improper handling of the mit_ssid_index argument, which can be manipulated by an attacker to overflow a stack buffer. This overflow can corrupt the stack, potentially allowing arbitrary code execution or causing denial of service. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 score of 9.3 reflects the critical nature of this flaw, highlighting its high impact on confidentiality, integrity, and availability. Although no known exploits have been observed in the wild, the public disclosure of exploit details increases the likelihood of active exploitation attempts. The vulnerability affects devices that may be deployed in enterprise and consumer environments, particularly where remote management interfaces are exposed to untrusted networks. The lack of patches at the time of disclosure necessitates immediate mitigation efforts to reduce exposure.

For European organizations, exploitation of CVE-2025-11418 could lead to full compromise of affected Tenda CH22 devices, enabling attackers to execute arbitrary code remotely. This could result in unauthorized access to internal networks, interception or manipulation of sensitive data, disruption of network services, and potential lateral movement within corporate environments. Critical infrastructure sectors relying on these devices for network connectivity or management could face operational disruptions or data breaches. The vulnerability’s remote, unauthenticated exploit vector increases the risk of widespread attacks, especially if devices are accessible from the internet or poorly segmented internal networks. The impact extends to confidentiality, integrity, and availability, threatening organizational security posture and compliance with European data protection regulations such as GDPR.

1. Immediately identify and inventory all Tenda CH22 devices within the network environment. 2. Restrict access to the management interface of these devices by implementing network segmentation and firewall rules limiting access to trusted IP addresses only. 3. Disable remote management features if not strictly necessary, especially on WAN interfaces. 4. Monitor network traffic for unusual requests targeting the /goform/AdvSetWrlsafeset endpoint or suspicious patterns indicative of exploitation attempts. 5. Engage with Tenda or authorized vendors to obtain firmware updates or patches as soon as they become available and apply them promptly. 6. Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability once available. 7. Educate network administrators about the vulnerability and ensure secure configuration practices are followed to minimize exposure. 8. If immediate patching is not possible, consider temporary mitigations such as web application firewalls (WAF) or reverse proxies to filter malicious requests.