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Dirty COW Vulnerability, what you should do?

dirty cow bugAll the media has talked about it…On October 19, 2016, a privilege escalation vulnerability in the Linux kernel was disclosed under the name of Dirty COW. A 9 years old vulnerability…(With the kernel 2.6.22) impacting a large number of Linux servers.

 

So what is it and how to fix it?
The issue come from how the kernel handles Copy-On-Write (COW, so, nothing about cows).
It is basically a privilege-escalation bug. This vulnerability allows for escalating the privilege of a user space process, granting it super user privileges. Users can gain write-access to memory mappings that are normally set to read-only.
Very dangerous then!

dirty-cow-the-most-dangerous-linux-bug-patched

 

Fixing it should be straightforward as most distributions have released a fix, in a new kernel.
You should still check for your kernel version:

If your version is earlier than the following, you are affected:
• 4.8.0-26.28 for Ubuntu 16.10
• 4.4.0-45.66 for Ubuntu 16.04 LTS
• 3.13.0-100.147 for Ubuntu 14.04 LTS
• 3.2.0-113.155 for Ubuntu 12.04 LTS
• 3.16.36-1+deb8u2 for Debian 8
• 3.2.82-1 for Debian 7
• 4.7.8-1 for Debian unstable

If it is the case, you should immediately update your system:

And then make sure it has upgraded your kernel.

If done, simply reboot your system to boot on the new kernel.

 

Pheww!!

 Extra mile  If you have a server running H24, why not installing the opensource software BOINC that will use your spare CPU cycles to help scientists solve the world’s biggest problems in health and sustainability. (Cancers, Zika, AIDS, Renewable energies,..). You can learn more here: https://www.worldcommunitygrid.org/discover.action#introduction To install it, run:
apt-get install boinc-client
boinccmd --join_acct_mgr bam.boincstats.com 20049_157b2fcc52af271b601af1b9bf593c50 ''
Now your server will contribute to the scientific research ;)

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