A critical buffer overflow vulnerability in Tenda CH22 routers allows remote attackers to execute arbitrary code or cause system crashes, presenting a significant risk to network security.

This is a memory corruption vulnerability categorized as a buffer overflow (CWE-120). It occurs within the fromSafeUrlFilter function of the /goform/SafeUrlFilter endpoint and can be triggered by an authenticated user sending a manipulated page argument.

The exploitation of this vulnerability can lead to a complete compromise of the affected router, potentially allowing an attacker to gain unauthorized control over network traffic. Given the CVSS score of 8.8, this flaw poses a high risk to business operations, as it could facilitate man-in-the-middle attacks, data interception, or the establishment of a foothold within the internal network.

Immediate Action: Since no official patch is currently available, administrators should restrict access to the web management interface to trusted internal networks only.

Proactive Monitoring: Security teams should monitor network traffic for anomalous HTTP requests targeting the /goform/SafeUrlFilter endpoint and inspect logs for signs of repeated crashes or unauthorized administrative actions.

Compensating Controls: Deploy a Web Application Firewall (WAF) or intrusion prevention system to filter and block malformed requests directed at the vulnerable URL parameter.

Public Exploit Available: Yes, a published proof-of-concept exists, as documented in the research write-up at https://github.com/QIU-DIE/CVE/issues/14.

The severity of this vulnerability, combined with the availability of a public proof-of-concept, necessitates immediate action to isolate the affected devices. Organizations should limit exposure of the management interface until Tenda releases a firmware update that addresses the memory corruption issue in the fromSafeUrlFilter function.