/usr/lib/x86_64-linux-gnu/libgsm0710.so is in libgsm0710-dev 1.2.2-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgsm0710.so.0.0.0
/usr/lib/x86_64-linux-gnu/libgsm0710.so.0.0.0