MLdonkey (up to 2.9.7) has a vulnerability that allows remote user to access any file with rights of running Mldonkey daemon by supplying a special-crafted request (ok, there's not much special about double slash) to an Mldonkey http GUI (tcp/4080 usually). Reference: https://savannah.nongnu.org/bugs/?25667 Thus, the exploit would be as simple as accessing any file on a remote host with your browser and double slash: http://mlhost:4080//etc/passwd