linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Several security issues were fixed in the Linux kernel.
- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems
- linux-kvm - Linux kernel for cloud environments
- linux-raspi2 - Linux kernel for Raspberry Pi 2
- linux-snapdragon - Linux kernel for Snapdragon processors
It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker in a guest virtual machine could use this to expose sensitive information (memory from other guests or the host OS). (CVE-2018-3646)
It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker could use this to expose sensitive information (memory from the kernel or other processes). (CVE-2018-3620)
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. (CVE-2018-5390)
Juha-Matti Tilli discovered that the IP implementation in the Linux kernel performed algorithmically expensive operations in some situations when handling incoming packet fragments. A remote attacker could use this to cause a denial of service. (CVE-2018-5391)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 16.04 LTS
- linux-image-4.4.0-1031-kvm - 4.4.0-1031.37
- linux-image-4.4.0-1065-aws - 4.4.0-1065.75
- linux-image-4.4.0-1094-raspi2 - 4.4.0-1094.102
- linux-image-4.4.0-1098-snapdragon - 4.4.0-1098.103
- linux-image-4.4.0-133-generic - 4.4.0-133.159
- linux-image-4.4.0-133-generic-lpae - 4.4.0-133.159
- linux-image-4.4.0-133-lowlatency - 4.4.0-133.159
- linux-image-4.4.0-133-powerpc-e500mc - 4.4.0-133.159
- linux-image-4.4.0-133-powerpc-smp - 4.4.0-133.159
- linux-image-4.4.0-133-powerpc64-emb - 4.4.0-133.159
- linux-image-4.4.0-133-powerpc64-smp - 4.4.0-133.159
- linux-image-aws - 22.214.171.1245.67
- linux-image-generic - 126.96.36.199.139
- linux-image-generic-lpae - 188.8.131.52.139
- linux-image-kvm - 184.108.40.2061.30
- linux-image-lowlatency - 220.127.116.11.139
- linux-image-powerpc-e500mc - 18.104.22.168.139
- linux-image-powerpc-smp - 22.214.171.124.139
- linux-image-powerpc64-emb - 126.96.36.199.139
- linux-image-powerpc64-smp - 188.8.131.52.139
- linux-image-raspi2 - 184.108.40.2064.94
- linux-image-snapdragon - 220.127.116.118.90
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
Please note that the recommended mitigation for CVE-2018-3646 involves updating processor microcode in addition to updating the kernel; however, the kernel includes a fallback for processors that have not received microcode updates.
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.