/usr/share/maven-repo/org/codehaus/plexus/plexus-utils/2.x/plexus-utils-2.x-javadoc.jar is in libplexus-utils2-java-doc 3.0.15-1+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/maven-repo/org/codehaus/plexus/plexus-utils/2.x/../3.0.15/plexus-utils-3.0.15-javadoc.jar