Core Security Technologies discovered a heap overflow vulnerability in dnsmasq when the TFTP service is enabled ('--enable-tftp'). If the configured tftp-prefix is sufficiently long, and a remote user sent a request which sends a long file name, dnsmasq could crash or, possibly, execute arbitrary code with root privileges.

The default tftp-prefix is /var/tftpd, which is short enough to make this difficult to exploit; if a longer prefix is used then arbitrary code execution may be possible. As well, Red Hat does not have TFTP support enabled by default.

dnsmasq 2.43 allows remote attackers to cause a denial of service (daemon crash) by (1) sending a DHCPINFORM while lacking a DHCP lease, or (2) attempting to renew a nonexistent DHCP lease for an invalid subnet as an "unknown client," a different vulnerability than CVE-2008-3214.

The tftprequest 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.