The libmaxminddb library provides a C library for reading MaxMind DB files, including the GeoIP2 databases from MaxMind.
libmaxminddb used uninitialised memory when reading from a corrupt database file.
A remote attacker could entice a user to use a specially crafted database with libmaxminddb, possibly resulting in a Denial of Service condition.
There is no known workaround at this time.
All libmaxminddb users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/libmaxminddb-1.4.3"