CVE-2020-25662: 
Linux Kernel vulnerability analysis and mitigation

A Red Hat only CVE-2020-12352 regression issue was found in the Linux kernel's Bluetooth stack implementation. The vulnerability affects Red Hat Enterprise Linux 8.3 GA kernel version kernel-4.18.0-240.el8 and derived kernels. This flaw allows a remote attacker in an adjacent range to leak small portions of stack memory on the system by sending specially crafted AMP (Alternate MAC-PHY Manager Protocol) packets (NVD, Red Hat).

The vulnerability stems from improper initialization of stack memory when handling certain AMP packets in the Linux kernel's Bluetooth stack implementation. The issue has 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:H/I:N/A:N, indicating adjacent network attack vector, low attack complexity, no privileges required, no user interaction needed, unchanged scope, high confidentiality impact, and no impact on integrity or availability (NVD).

The highest threat from this vulnerability is to data confidentiality, as it allows attackers within Bluetooth range to leak small portions of stack memory from the affected system. The vulnerability specifically affects Red Hat Enterprise Linux 8.3 GA release, as it was a regression of the original CVE-2020-12352 fix (Red Hat).

To mitigate the vulnerability, users can disable Bluetooth functionality via blocklisting kernel modules in the Linux kernel using system-wide modprobe rules. Alternatively, Bluetooth can be disabled within the hardware or at BIOS level. Red Hat has released fixes through RHSA-2020:4685 for the kernel package and RHSA-2020:4686 for the kernel-rt package (Red Hat Bugzilla).