CVE-2025-12322 is a buffer overflow vulnerability identified in Tenda CH22 router firmware version 1.0.0.1. The vulnerability resides in the fromNatStaticSetting function, specifically in the handling of the 'page' argument within the /goform/NatStaticSetting HTTP endpoint. Improper validation or bounds checking of this argument allows an attacker to overflow a buffer, potentially overwriting adjacent memory. This can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, significantly increasing its risk profile. The CVSS 4.0 score of 8.7 reflects the ease of exploitation (network vector, low complexity), lack of required privileges or user interaction, and the high impact on confidentiality, integrity, and availability. While no active exploitation has been reported, a public exploit is available, which could facilitate attacks by less skilled adversaries. The affected product, Tenda CH22, is a consumer-grade router commonly deployed in small offices and homes, but may also be present in some enterprise or critical infrastructure environments. The absence of an official patch at the time of publication necessitates interim mitigations to reduce exposure.

For European organizations, exploitation of this vulnerability could lead to severe consequences including unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network services. The ability to execute arbitrary code remotely on network infrastructure devices like routers can enable attackers to establish persistent footholds, pivot to other internal systems, or launch further attacks such as man-in-the-middle or ransomware campaigns. Given the router’s role as a network gateway, compromise could affect the confidentiality and integrity of communications and data flows. Organizations relying on Tenda CH22 devices in critical sectors such as finance, healthcare, government, or energy may face operational disruptions and data breaches. The public availability of exploits increases the likelihood of opportunistic attacks targeting vulnerable devices across Europe.

Immediate mitigation should focus on network-level protections: restrict access to the /goform/NatStaticSetting endpoint by implementing firewall rules or access control lists to block external and untrusted internal traffic. Monitor network traffic for unusual requests targeting this endpoint and deploy intrusion detection/prevention systems with signatures for this exploit. Organizations should prioritize obtaining and applying firmware updates from Tenda once available. If official patches are delayed, consider isolating affected devices from critical network segments or replacing them with devices from vendors with timely security support. Regularly audit network devices for vulnerable firmware versions and maintain an inventory to ensure rapid response. Additionally, implement network segmentation to limit the impact of any potential compromise and enforce strong authentication and encryption on management interfaces to reduce attack surface.