CVE-2025-20684 is a security vulnerability identified in MediaTek's wireless LAN (wlan) Access Point (AP) driver affecting the MT7615, MT7622, and MT7663 chipsets. The root cause of the vulnerability is an out-of-bounds write due to an incorrect bounds check within the wlan AP driver code. This type of vulnerability, classified under CWE-787, allows an attacker to write data outside the intended memory buffer boundaries, potentially leading to memory corruption. Exploitation of this flaw requires the attacker to have user-level execution privileges on the affected device but does not require user interaction, meaning the exploit can be triggered automatically once the attacker has the necessary access. The vulnerability could enable a local escalation of privilege, allowing an attacker with limited user rights to gain higher privileges, possibly root or kernel-level access, thereby compromising the confidentiality, integrity, and availability of the device. The affected versions include SDK release 5.1.0.0 and earlier, indicating that devices running these versions of MediaTek's SDK are vulnerable. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The issue was reserved in November 2024 and published in July 2025. The vendor has assigned a patch ID (WCNCR00416939) and issue ID (MSV-3422), but no public patch links are currently available. Given the nature of the vulnerability in wireless AP drivers, exploitation could affect network infrastructure devices such as routers, gateways, and IoT devices using these chipsets, potentially allowing attackers to gain control over network traffic or disrupt network services.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and service providers relying on network equipment powered by MediaTek MT7615, MT7622, and MT7663 chipsets. Successful exploitation could lead to local privilege escalation on network devices, enabling attackers to execute arbitrary code with elevated privileges. This could result in unauthorized access to sensitive network configurations, interception or manipulation of network traffic, and potential lateral movement within corporate networks. The impact extends to critical infrastructure sectors that depend on secure and reliable wireless connectivity, such as telecommunications, finance, healthcare, and government agencies. The lack of user interaction requirement increases the risk of automated exploitation once an attacker gains user-level access, potentially through other vulnerabilities or compromised accounts. Additionally, the vulnerability could be leveraged to disrupt availability by causing device crashes or reboots. The absence of known exploits in the wild currently limits immediate risk, but the presence of a local privilege escalation vector in widely deployed wireless drivers necessitates prompt attention to prevent future attacks.

European organizations should prioritize the following mitigation steps: 1) Inventory and identify all network devices and IoT equipment using MediaTek MT7615, MT7622, or MT7663 chipsets, particularly those running SDK release 5.1.0.0 or earlier. 2) Engage with device vendors and MediaTek to obtain and apply official patches or firmware updates addressing CVE-2025-20684 as soon as they become available. 3) Implement strict access controls to limit user-level access to network devices, reducing the attack surface for local privilege escalation. 4) Monitor network devices for unusual behavior or signs of exploitation, including unexpected privilege escalations or memory corruption symptoms. 5) Employ network segmentation to isolate critical infrastructure and sensitive systems from devices potentially vulnerable to this flaw. 6) Where patching is delayed, consider temporary mitigations such as disabling or restricting wireless AP functionalities on affected devices if feasible. 7) Maintain up-to-date asset management and vulnerability scanning to detect unpatched devices. 8) Educate IT and security teams about the vulnerability to ensure rapid response and remediation.