Hello and welcome to the forums.
I have had that quite some time.
It looks like Steam uses old libs for Ubuntu still. Please try the following:
Code:
rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6
rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libgcc_s.so.1
You might wanna make a backup of the files just in case before deleting them.