Tenda F456 Router Buffer Overflow Vulnerability (CVE-2026-7030)

A critical security vulnerability, tracked as CVE-2026-7030, has been identified in Tenda F456 router version 1.0.0.5. The vulnerability resides within the fromRouteStatic function of the /goform/RouteStatic file. Successful exploitation of this flaw allows a remote attacker to execute arbitrary code due to a buffer overflow. The vulnerability is triggered by manipulating the page argument. Publicly available exploit code exists, increasing the risk of widespread exploitation. This vulnerability poses a significant threat to organizations and individuals using the affected Tenda router model, as it could lead to complete system compromise.

Attack Chain

1. Attacker identifies a Tenda F456 router version 1.0.0.5 exposed to the internet.
2. The attacker crafts a malicious HTTP request targeting the /goform/RouteStatic endpoint.
3. The HTTP request includes the page argument with a payload exceeding the expected buffer size within the fromRouteStatic function.
4. The fromRouteStatic function processes the oversized page argument without proper bounds checking.
5. The buffer overflow overwrites adjacent memory regions, potentially including critical program data or execution pointers.
6. The attacker redirects execution flow to injected malicious code within the overflowed buffer.
7. The injected code executes with the privileges of the web server process.
8. The attacker gains complete control of the router, potentially leading to data exfiltration, denial of service, or further network compromise.

Impact

Successful exploitation of CVE-2026-7030 allows a remote attacker to gain complete control of the affected Tenda F456 router. This could lead to a variety of malicious activities, including data exfiltration, modification of router settings, DNS hijacking, and deployment of malware onto connected devices. Given the publicly available exploit code, a widespread attack is possible, impacting potentially thousands of users who have not applied appropriate mitigations.

Recommendation

• Apply any available firmware updates for Tenda F456 routers from the vendor's website immediately to patch CVE-2026-7030.
• Monitor web server logs for suspicious requests targeting the /goform/RouteStatic endpoint with unusually long page parameters using the provided Sigma rule.
• Implement network intrusion detection system (IDS) rules to detect and block exploitation attempts targeting CVE-2026-7030.