Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP server. It includes support for Trivial FTP (TFTP).
Multiple vulnerabilities have been reported in the TFTP functionality included in Dnsmasq:
A remote attacker in the local network could exploit these vulnerabilities by sending specially crafted TFTP requests to a machine running Dnsmasq, possibly resulting in the remote execution of arbitrary code with the privileges of the user running the daemon, or a Denial of Service. NOTE: The TFTP server is not enabled by default.
You can disable the TFTP server either at buildtime by not enabling the "tftp" USE flag, or at runtime. Make sure "--enable-tftp" is not set in the DNSMASQ_OPTS variable in the /etc/conf.d/dnsmasq file and "enable-tftp" is not set in /etc/dnsmasq.conf, either of which would enable TFTP support if it is compiled in.
All Dnsmasq users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/dnsmasq-2.5.0"