A Linux kernelsecurity update has been released for Ubuntu Linux 18.04 LTS and 20.04 LTS.

LSN-0073-1: Linux kernel vulnerability

Linux kernel vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
- Ubuntu 20.04 LTS

Summary

Several security issues were fixed in the kernel.

Software Description

- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems - linux-azure - Linux kernel for Microsoft Azure Cloud systems - linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems - linux-oem - Linux kernel for OEM systems

Details

Andy Nguyen discovered that the Bluetooth L2CAP implementation in the Linux kernel contained a type-confusion error. A physically proximate remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-12351)

Andy Nguyen discovered that the Bluetooth A2MP implementation in the Linux kernel did not properly initialize memory in some situations. A physically proximate remote attacker could use this to expose sensitive information (kernel memory). (CVE-2020-12352)

Andy Nguyen discovered that the Bluetooth HCI event packet parser in the Linux kernel did not properly handle event advertisements of certain sizes, leading to a heap-based buffer overflow. A physically proximate remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-24490)

Update instructions

The problem can be corrected by updating your kernel livepatch to the following versions:

Ubuntu 18.04 LTS
aws - 73.1
generic - 73.1
lowlatency - 73.1
oem - 73.1

Ubuntu 20.04 LTS
aws - 73.1
azure - 73.1
gcp - 73.1
generic - 73.1
lowlatency - 73.1

Support Information

Kernels older than the levels listed below do not receive livepatch updates. If you are running a kernel version earlier than the one listed below, please upgrade your kernel as soon as possible.

Ubuntu 18.04 LTS
linux-aws - 4.15.0-1054
linux-azure - 5.0.0-1025
linux-gcp - 5.0.0-1025
linux-oem - 4.15.0-1063
linux - 4.15.0-69

Ubuntu 20.04 LTS
linux-aws - 5.4.0-1009
linux-azure - 5.4.0-1010
linux-gcp - 5.4.0-1009
linux-oem - 5.4.0-26
linux - 5.4.0-26

Ubuntu 16.04 LTS
linux-aws - 4.4.0-1098
linux-azure - 4.15.0-1063
linux-hwe - 4.15.0-69
linux - 4.4.0-168

Ubuntu 14.04 ESM
linux-lts-xenial - 4.4.0-168

References

- CVE-2020-12351
- CVE-2020-12352
- CVE-2020-24490