Avolicious
Before 15.5:
DDNet.exe started -> Download server list from master(1,2,3,4).teeworlds.com -> Pings all servers
Problem? It leaks your ip to all servers, so you easily could use player ip addresses for dos attacks
Now/After 15.5:
DDNet.exe started -> Downloading from HTTPS master server -> No IP leakage because you dont ping any server