Ubuntu 18.04 LTS Denial Of Service Threat Advisory: USN-3732-1

ubuntu

August 6, 2018

The system could be made unavailable if it received specially craftednetwork traffic.

Summary

The system could be made unavailable if it received specially crafted

network traffic.

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-kvm: Linux kernel for cloud environments

- linux-oem: Linux kernel for OEM processors- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

Juha-Matti Tilli discovered that the TCP implementation in the Linux kernel

performed algorithmically expensive operations in some situations when

handling incoming packets. A remote attacker could use this to cause a

denial of service.

Topics Covered

security advisory denial of service critical system update ubuntu network attack linux kernel

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1013-oem     4.15.0-1013.16
  linux-image-4.15.0-1015-gcp     4.15.0-1015.15
  linux-image-4.15.0-1017-aws     4.15.0-1017.17
  linux-image-4.15.0-1017-kvm     4.15.0-1017.17
  linux-image-4.15.0-1018-raspi2  4.15.0-1018.19
  linux-image-4.15.0-1019-azure   4.15.0-1019.19
  linux-image-4.15.0-30-generic   4.15.0-30.32
  linux-image-4.15.0-30-generic-lpae  4.15.0-30.32
  linux-image-4.15.0-30-lowlatency  4.15.0-30.32
  linux-image-4.15.0-30-snapdragon  4.15.0-30.32
  linux-image-aws                 4.15.0.1017.17
  linux-image-azure               4.15.0.1019.19
  linux-image-azure-edge          4.15.0.1019.19
  linux-image-gcp                 4.15.0.1015.17
  linux-image-generic             4.15.0.30.32
  linux-image-generic-lpae        4.15.0.30.32
  linux-image-gke                 4.15.0.1015.17
  linux-image-kvm                 4.15.0.1017.17
  linux-image-lowlatency          4.15.0.30.32
  linux-image-oem                 4.15.0.1013.15
  linux-image-raspi2              4.15.0.1018.16
  linux-image-snapdragon          4.15.0.30.32

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.