CVE-2025-12235 is a buffer overflow vulnerability identified in the Tenda CH22 router firmware version 1.0.0.1. The flaw exists in the fromSetIpBind function within the /goform/SetIpBind endpoint, where improper handling of the 'page' argument allows an attacker to overflow a buffer. This vulnerability requires the attacker to be on the local network and possess low privileges, but does not require user interaction or authentication beyond local network access. The buffer overflow can lead to arbitrary code execution or cause the device to crash, compromising the confidentiality, integrity, and availability of the router and potentially the entire network it supports. The vulnerability has a CVSS 4.0 base score of 8.6, reflecting high severity due to its low attack complexity and significant impact on all security properties. Although no active exploits have been reported in the wild, the exploit code has been publicly disclosed, increasing the risk of exploitation. The vulnerability affects only firmware version 1.0.0.1 of the Tenda CH22, a consumer-grade router commonly used in residential and small office environments. The attack vector is local network access, which may be achieved through compromised devices or insider threats. No official patches or mitigations have been published yet, highlighting the need for immediate defensive measures.

The impact of CVE-2025-12235 is significant for organizations and individuals using the Tenda CH22 router version 1.0.0.1. Exploitation can lead to arbitrary code execution on the router, allowing attackers to gain control over the device. This can result in interception or manipulation of network traffic, disruption of network services, and potential pivoting to other internal systems. Confidential data passing through the router could be exposed or altered, undermining data integrity and privacy. Availability of network services may be compromised if the device is crashed or rebooted maliciously. Since the attack requires local network access, environments with weak internal network segmentation or compromised endpoints are at higher risk. The public availability of exploit code increases the likelihood of attacks, especially in environments where patching is delayed or unsupported. Small businesses and home users relying on this router model may be particularly vulnerable due to limited security monitoring and response capabilities.

To mitigate CVE-2025-12235, organizations should first check for firmware updates from Tenda addressing this vulnerability and apply them promptly once available. In the absence of official patches, network administrators should implement strict internal network segmentation to limit access to the router's management interfaces only to trusted devices. Disable or restrict access to the /goform/SetIpBind endpoint if possible, using firewall rules or router configuration settings. Monitor local network traffic for unusual requests targeting the vulnerable endpoint. Employ network intrusion detection systems (NIDS) with signatures for known exploit attempts once they become available. Educate users about the risks of connecting untrusted devices to the local network. Consider replacing affected devices with models that have active security support if patching is not feasible. Regularly audit router configurations and access logs to detect potential exploitation attempts early.