We have a dedicated Linux server, where we store all builds of our software. The Linux server is running the current samba version. Samba is configured with 'security=user' and the shares are read/write for guest, so no authentication is required.
If I add a new CIFS Share, leave username and password blank and test the configuration, I get the following error message:

Cannot read share (or directory on share)
jenkins.plugins.publish_over.BapPublisherException: Exception when testing config. URL [smb://...], Message: [Logon failure: unknown user name or password.]

This message also occurs if I use the plugin as post build step.

So currently we can't use this plugin in our build environment.

I had a quick look in the source code and maybe there is a problem in the createSmbFile(final String url) function in CifsClient.java because I don't know, if 'auth' can ever be null and therefore the else path can never be reached.