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 2.63test1, when used with certain libvirt configurations, replies to requests from prohibited interfaces, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed DNS query.

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.

The tftp_request function in tftp.c in dnsmasq before 2.50, when --enable-tftp is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a TFTP read (aka RRQ) request with a malformed blksize option.

Heap-based buffer overflow in the tftp_request function in tftp.c in dnsmasq before 2.50, when --enable-tftp is used, might allow remote attackers to execute arbitrary code via a long filename in a TFTP packet, as demonstrated by a read (aka RRQ) request.

dnsmasq 2.25 allows remote attackers to cause a denial of service (daemon crash) by (1) renewing a nonexistent lease or (2) sending a DHCPREQUEST for an IP address that is not in the same network, related to the DHCP NAK response from the daemon.

Dnsmasq before 2.21 allows remote attackers to poison the DNS cache via answers to queries that were not made by Dnsmasq.