GNU Wget 1.12 and earlier uses a server-provided filename instead of the original URL to determine the destination filename of a download, which allows remote servers to create or overwrite arbitrary files via a 3xx redirect to a URL with a .wgetrc filename followed by a 3xx redirect to a URL with a crafted filename, and possibly execute arbitrary code as a consequence of writing to a dotfile in a home directory.

GNU Wget before 1.12 does not properly handle a '\0' character in a domain name in the Common Name field of an X.509 certificate, which allows man-in-the-middle remote attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.