A security issue has been discovered in jCIFS, which allows a malicious person to authenticate with an invalid username. The problem is that it is possible to authenticate with any username if the guest account is enabled on a CIFS server.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/33528/sa11791.txt
Source: https://packetstormsecurity.com/files/33528/Secunia-Security-Advisory-11791.html