/usr/lib/x86_64-linux-gnu/libcec-platform.so is in libcec-platform-dev 1.0.10+dfsg1-8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcec-platform.so.1
/usr/lib/x86_64-linux-gnu/libcec-platform.so.1