/usr/share/doc/texlive-doc/plain/cweb/cwebman.dvi.gz is in texlive-extra-utils 2009-10ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/texlive-doc/plain/cweb/../../../texlive-extra-utils/plain/cweb/cwebman.dvi.gz