A massive DDoS (distributed denial-of-service) attack against a popular cloud-based DNS provider Dyn.COM took down major websites. The DYN.COM confirmed it on twitter:
Following sites are having issues due to DNS problems:
- Business Insider
- HBO Now
- The Verge
- Wired and more
You can verify NS with the following standard Unix command:
$ host -t ns twitter.com
twitter.com name server ns2.p34.dynect.net.
twitter.com name server ns1.p34.dynect.net.
twitter.com name server ns4.p34.dynect.net.
twitter.com name server ns3.p34.dynect.net.
From the official announcement:
This attack is mainly impacting US East and is impacting Managed DNS customers in this region. Our Engineers are continuing to work on mitigating this issue. Services have been restored to normal as of 13:20 UTC on 21/Oct/2016. But, I’m still seeing problems.
This DDoS attack may also be impacting Dyn Managed DNS advanced services with possible delays in monitoring. Our Engineers are continuing to work on mitigating this issue. — Oct 21, 2016 – 16:48 UTC
See the “DDoS Attack Against Dyn Managed DNS” update page for up to date information.
A race condition was found in the way the Linux kernel’s memory subsystem handled the copy-on-write (COW) breakage of private read-only memory mappings. A local unprivileged user could use this flaw to gain write access to otherwise read-only memory mappings and thus increase their privileges on the system. In other words, the normal user can overwrite files they are allowed just to read it. For example, /etc/passwd can be edited or deleted by a normal user. The vulnerability easily exploited with a local shell account.
How old is this bug?
I can not belive, but bug existed for in the kernel for eleven years, to give normal users full root access.
How do I fix my server or desktop powered by Linux?
Apply fix ASAP:
If you just want the Kernel patch to go here.
What about my Android phone?
You need to wait to get an update (also known as firmware ROM) from your phone manufacturer.
SSH keys provide a better and secure way of logging into a server with SSH than using a password. If you are a sysadmin or programmer, you may need to use SSH to fix server or update code. This guide explains how to setup SSH keys securely between your server and client computer.
Kernel live patching enables runtime correction of critical security issues in running kernel without rebooting. Try new service from Canonical the company behind Ubuntu Linux operating system. It uses upstream Linux kernel 4.x kpatch technology. This guide explains how to enable or patch your Ubuntu Linux 16.04 LTS server without rebooting the box.