/usr/share/doc/cain/changelog.Debian.gz is in cain 1.10+dfsg-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/cain/../cain-solvers/changelog.Debian.gz
/usr/share/doc/cain/../cain-solvers/changelog.Debian.gz