Security [September 2017] Redhat/CentOS Linux Kernel Security Update CVE-2017-1000253

Redhat & CentOS 6.x and CentOS 7.3 and lower have a new Linux Kernel security update for security vulnerability CVE-2017-1000253. OpenVZ VPS users don't use their own Linux Kernels like dedicated, KVM or Xen users so need to make sure their OpenVZ VPS provider's host node kernel is updated.

Info

• https://www.qualys.com/2017/09/26/cve-2017-1000253/cve-2017-1000253.txt

Updating Linux Kernel

So need to do 2 steps for non-openvz systems. For openvz vps you use host node kernel and not your own so only your web host can update the host node kernel so contact them. Some openvz vps providers also use KernelCare so are auto patched up but some don't.

1. Do a yum update
   Code (Text):

   yum -y update

   then check if updated kernel version is updated via
   Code (Text):

   yum list kernel

   output
2. Then reboot your server for Kernel update to take effect. If you use KernelCare KernelCare rebootless kernel updates - CentminMod.com LEMP Nginx web stack for CentOS they auto patch your kernel every 4hrs and do not require server reboots. Then verify after reboot of kernel version via
   Code (Text):

   uname -r

   or if using KernelCare via
   Code (Text):

   kcare-uname -r

Update SSH Commands

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Updating yum packages via yum update

Code (Text):

yum -y update

After update and server reboot verify updated kernel with command

Code (Text):

uname -r

or if using KernelCare via

Code (Text):

kcare-uname -r

Summary

• Redhat/CentOS 6.x users need to update to Linux Kernel 2.6.32-696.10.3 as per https://access.redhat.com/errata/RHSA-2017:2795 and then reboot their servers.
• Redhat/CentOS 7.x users best to update to 7.4 OS which has fixed Linux Kernel 3.10.0-693 or higher.