CVE-2024-42940 identifies a stack-based buffer overflow vulnerability in the Tenda FH1201 router firmware version 1.2.0.14 (build 408). The vulnerability arises from improper input validation of the 'page' parameter within the fromP2pListFilter function. When a specially crafted POST request containing a maliciously crafted 'page' parameter is sent to the device, it triggers a stack overflow condition. This overflow can overwrite the stack memory, leading to a crash of the router's firmware process, resulting in a Denial of Service (DoS). The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow). The attack vector is adjacent network (AV:A), requiring low attack complexity (AC:L) and low privileges (PR:L), with no user interaction (UI:N) needed. The scope is unchanged (S:U), and the impact affects availability only (A:H), with no impact on confidentiality or integrity. No patches or exploits are currently publicly available, but the vulnerability poses a risk to network stability and device availability. The flaw could be leveraged by attackers with network access to disrupt connectivity for users relying on this router model.

The primary impact of CVE-2024-42940 is the potential for Denial of Service on affected Tenda FH1201 routers. This can disrupt internet connectivity and network services for individuals or organizations relying on these devices. In environments where these routers are used as critical network gateways, such as small offices or home offices, the DoS could lead to operational downtime and loss of productivity. Although the vulnerability does not allow for data theft or device takeover, the loss of availability can affect business continuity and user experience. Since exploitation requires network access with low privileges, attackers on the same local or adjacent network segment could exploit this vulnerability to cause service interruptions. The absence of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks once exploit code becomes available. Organizations using this router model should consider the impact on network reliability and plan accordingly.

To mitigate CVE-2024-42940, organizations should first verify if they are using the Tenda FH1201 router with firmware version 1.2.0.14 (408). Since no official patch is currently available, immediate mitigation steps include restricting access to the router's management interface to trusted networks only, ideally via VLAN segmentation or firewall rules that block unauthorized POST requests to the vulnerable function. Network administrators should disable remote management features if enabled and monitor network traffic for unusual POST requests targeting the router. Implementing network segmentation to isolate IoT and consumer-grade routers from critical infrastructure can reduce risk. Regularly check Tenda's official channels for firmware updates addressing this vulnerability and apply patches promptly once released. Additionally, consider replacing affected devices with models from vendors with stronger security track records if mitigation is not feasible. Employ network monitoring tools to detect and alert on anomalous traffic patterns indicative of exploitation attempts.