How do I update it to 2.32?

Ideally, you don't. glibc is the most central library on the system. Basically everything depends on it. If something goes wrong during the update or if there is an unexpected incompatibility, the whole system breaks and you won't even be able to use the most basic tools to fix it.

Instead, you could upgrade your whole system to a newer version of Ubuntu. Or you could run a newer version of Ubuntu in a chroot/container/VM. Or you could complie openmw-validator for your version of glibc (assuming its source code is available and can be compiled).

As j0h described, I was able to solve my problem. Here is what I have done:

1. I read at Wikipedia about glibc. Glibc (better known as GNU C Library) has a fork for linux which is called libc6. Libc6 is available via apt.
2. Run apt-get update to update the database.
3. Use apt-cache policy libc6 to find out the installed version and the candidate version, whereas the installed version can be also shown with ldd --version.
4. Install the new candidate version with apt-get install libc6
5. Check the new version again by doing step 3 again to see your success.

I was able to install libc6 2.17 in Debian Wheezy by editing the recommendations in perror's answer:

IMPORTANT

You need to exit out of your display manager by pressing CTRL+ALT+F1. Then you can stop x (slim) with sudo /etc/init.d/slim stop

(replace slim with mdm or lightdm or whatever)

Add the following line to the file /etc/apt/sources.list:

deb http://ftp.debian.org/debian experimental main

Should be changed to:

deb http://ftp.debian.org/debian sid main

Then follow the rest of perror's post:

Update your package database:

apt-get update

Install the glibc package:

apt-get -t sid install libc6-amd64 libc6-dev libc6-dbg

IMPORTANT

After updating libc6, restart the computer, and you should comment out or remove the sid source you just added (deb http://ftp.debian.org/debian sid main), or else you risk upgrading your whole distro to sid.

Check it is actually needed

Firstly check the python application as it could be out of date and is probably misreading the glibc version. CentOS shows the base version as installed and is patched to keep up with changes and it could just be a case of fixing the version that is being looked for in the code as a quick fix, but if the application is being actively developed you need to let the developers know or fork it for yourself if you can.

An up to date glibc on CentOS 7 should be 2.17-196.el7_4.2

If it is needed, Containerise

If it's absolutely necessary to run this application, the official RHEL approach would be to containerize, but you would still need to provide a working glibc, which wouldn't be possible with stock CentOS 7.

As a last resort, install glibc in a nonstandard location

If this isn't viable, and as an absolute last resort, it is possible to install a newer version of glibc than 2.18 as that is 9 years old now and glibc has been updated for several vulnerabilities and I'm not sure off the top of my head if it will build with the version of make in CentOS 7, but any newer version should work as follows:

• This can potentially affect the functionality of your computer so make sure you know what you are doing

You can build the version of glibc you require elsewhere on your server and add it to LD_LIBRARY_PATH for the application. Note this must only be done for the application only.

wget http://ftp.gnu.org/gnu/glibc/glibc-2.18.tar.gz
tar zxvf glibc-2.18.tar.gz
cd glibc-2.18
mkdir build
cd build
../configure --prefix=/opt/glibc-2.18
make -j4
sudo make install

Then to run a binary you need to use patchelf to update its interpreter

patchelf --set-interpreter /opt/glibc-2.18/lib/ld-linux-x86-64.so.2 program_you_are_running

And you need to enable it to find the new glibc library, either by

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/glibc-2.18/lib

Or you can use patchelf to update the binary's rpath (you can combine this with the previous pathelf command)

patchelf --set-rpath /opt/glibc-2.18/lib:/usr/lib64 program_you_are_running

If you change LD_LIBRARY_PATH don't export it for the whole system because all the binaries unmodified by patchelf will segfault.

/opt is the standard place to install third-party applications and libraries but you can use any path away from the system paths.