The ftpsyst function in ftp-basic.c in Free Software Foundation (FSF) GNU wget 1.10.2 allows remote attackers to cause a denial of service (application crash) via a malicious FTP server with a large number of blank 220 responses to the SYST command.
wget 1.8.x and 1.9.x allows a remote malicious web server to overwrite certain files via a redirection URL containing a ".." that resolves to the IP address of the malicious server, which bypasses wget's filtering for ".." sequences.
wget 1.8.x and 1.9.x does not filter or quote control characters when displaying HTTP responses to the terminal, which may allow remote malicious web servers to inject terminal escape sequences and execute arbitrary code.