aria2 is a download utility with resuming and segmented downloading with HTTP/HTTPS/FTP/BitTorrent support.
A directory traversal vulnerability was discovered in aria2.
A remote attacker could entice a user to download from a specially crafted metalink file, resulting in the creation of arbitrary files.
There is no known workaround at this time.
All aria2 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/aria2-1.9.3"