Directory traversal vulnerability in the SFTP/SSH2 virtual server in Xlight FTP Server 3.5.0, 3.5.5, and possibly other versions before 3.6 allows remote authenticated users to read, overwrite, or delete arbitrary files via .. (dot dot) sequences in the (1) ls, (2) rm, (3) rename, and other unspecified commands.
https://exchange.xforce.ibmcloud.com/vulnerabilities/60151
http://www.xlightftpd.com/whatsnew.htm
http://www.securityfocus.com/archive/1/512192/100/0/threaded