Dnsmasq is "a lightweight DNS, TFTP, PXE, router advertisement and DHCP server. It is intended to provide coupled DNS and DHCP service to a LAN". A number of vulnerabilities have been found that allow remote code execution and denial of service attacks.
Discovery is not vulnerable. Only one of the vulnerabilities, CVE-2017-14491, applies to RHEL/CentOS 6 and exists in the dnsmasq, dnsmasq-debuginfo and dnsmasq-utils packages - which we do not install on the appliance.