dnsmasq: A flaw was found in dnsmasq before 2.83

A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerabilitywas discovered in the way dnsmasq extract names from DNS packets beforevalidating them with DNSSEC data. An attacker on the network, who cancreate valid DNS replies, could use this flaw to cause an overflow witharbitrary data in a heap-allocated memory, possibly executing code on themachine. The flaw is in the rfc1035.c:extract_name() function, which writesdata to the memory pointed by name assuming MAXDNAME*2 bytes are availablein the buffer. However, in some code execution paths, it is possibleextract_name() gets passed an offset from the base buffer, thus reducing,in practice, the number of available bytes that can be written in thebuffer. The highest threat from this vulnerability is to dataconfidentiality and integrity as well as system availability.

Where it's fixed