David Kierznowski discovered that libcurl, a multi-protocol file transfer library, when configured to follow URL redirects automatically, does not question the new target location. As libcurl also supports file:// and scp:// URLs - depending on the setup - an untrusted server could use that to expose local files, overwrite local files or even execute arbitrary code via a malicious URL redirect. This update introduces a new option called CURLOPT_REDIR_PROTOCOLS which by default does not include the scp and file protocol handlers.