The c-ares function `ares_parse_naptr_reply()`, which is used for parsing NAPTR responses, could be triggered to read memory outside of the given input buffer if the passed in DNS response packet was crafted in a particular way.

Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly execute arbitrary code via a hostname with an escaped trailing dot.