Is there a way to get the last commit message without access to the repo? svn log --limit 1 tries to connect to the repo.
EDIT: I have credentials setu
I believe any action on a SVN repository uses the SVN repository's credential settings. However, if you have access on the server where the SVN repository is being hosted, you could create a own script to read out {repository-root}/db/revprops folder. Here you can find all the revision commit messages.