In dnsmasq before 2.78, if the DNS packet size does not match the expected size, the size parameter in a memset call gets a negative value. As it is an unsigned value, memset ends up writing up to 0xffffffff zero's (0xffffffffffffffff in 64 bit platforms), making dnsmasq crash.

Dnsmasq before 2.76 allows remote servers to cause a denial of service (crash) via a reply with an empty DNS address that has an (1) A or (2) AAAA record defined locally.

The tcp_request function in Dnsmasq before 2.73rc4 does not properly handle the return value of the setup_reply function, which allows remote attackers to read process memory and cause a denial of service (out-of-bounds read and crash) via a malformed DNS request.

Dnsmasq before 2.66test2, when used with certain libvirt configurations, replies to queries from prohibited interfaces, which allows remote attackers to cause a denial of service (traffic amplification) via spoofed TCP based DNS queries. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-3411.