cURL is a command line tool for transferring files with URL syntax, supporting numerous protocols.
David Kierznowski reported that the redirect implementation accepts arbitrary Location values when CURLOPT_FOLLOWLOCATION is enabled.
A remote attacker could possibly exploit this vulnerability to make remote HTTP servers trigger arbitrary requests to intranet servers and read or overwrite arbitrary files via a redirect to a file: URL, or, if the libssh2 USE flag is enabled, execute arbitrary commands via a redirect to an scp: URL.
There is no known workaround at this time.
All cURL users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/curl-7.19.4"