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 done updating libc6, restart 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.