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.
For the oldstable distribution (etch) this problem has been fixed in version 7.15.5-1etch2.
For the stable distribution (lenny) this problem has been fixed in version 7.18.2-8lenny2.
For the unstable distribution (sid) this problem has been fixed in version 7.18.2-8.1.
We recommend that you upgrade your curl packages.
MD5 checksums of the listed files are available in the original advisory.