/usr/share/man/man8/mwdisext.8.gz is in mediawiki-extensions-base 3.5~deb7u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man8/mwenext.8.gz
/usr/share/man/man8/mwenext.8.gz