CVE-2025-20694: 
NixOS vulnerability analysis and mitigation

In Bluetooth FW, there is a possible system crash due to an uncaught exception that could lead to remote denial of service. The vulnerability (CVE-2025-20694) was discovered and disclosed in July 2025, affecting various MediaTek chipsets and software versions including Android 13.0, 14.0, 15.0, SDK release 3.7 and earlier versions, and OpenWRT 21.02 and 23.05 (MediaTek Bulletin).

The vulnerability is classified as a Buffer Underflow (CWE-124) in the Bluetooth firmware. It has been assigned a CVSS v3.1 Base Score of 6.5 (Medium) with the vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating adjacent network attack vector, low attack complexity, no privileges required, and no user interaction needed for exploitation (NVD).

The vulnerability can result in a system crash leading to remote denial of service. No additional execution privileges are needed for exploitation, and user interaction is not required. The impact is primarily focused on system availability, with no direct impact on confidentiality or integrity (MediaTek Bulletin).

MediaTek has released patches for the affected systems and notified device OEMs of the security patches at least two months before publication. Users are advised to update their devices to the latest firmware versions that include these security patches (MediaTek Bulletin).