Multiple stack-based buffer overflows in the (1) senddg and (2) sendvc functions in the libresolv library in the GNU C Library (aka glibc or libc6) before 2.23 allow remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted DNS response that triggers a call to the getaddrinfo function with the AFUNSPEC or AFINET6 address family, related to performing "dual A/AAAA DNS queries" and the libnss_dns.so.2 NSS module.