Comment 31 for bug 1352504

@Blaine Fleming - ah, thanks!
For anyone else in a panic, here's what I did.

   # /etc/init.d/nscd stop
   # sudo add-apt-repository ppa:ubuntu-security-proposed/ppa
   # aptitude update
   # aptitude safe-upgrade

and you shoudl see updates from the new ppa:

   ...
   The following packages will be upgraded:
     libc-bin libc-dev-bin libc6 libc6-dev libc6-i386 nscd
   6 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
   Need to get 12.2MB of archives. After unpacking 4,096B will be used.
   Do you want to continue? [Y/n/?] y
   Writing extended state information... Done
   ...