An issue was discovered in PHP 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.2. dns_get_record misparses a DNS response, which can allow a hostile DNS server to cause PHP to misuse memcpy, leading to read operations going past the buffer allocated for DNS data. This affects php_parserr in ext/standard/dns.c for DNS_CAA and DNS_ANY queries.