The getaddrinfo function in glibc before 2.15, when compiled with libidn and the AI_IDN flag is used, allows context-dependent attackers to cause a denial of service (invalid free) and possibly execute arbitrary code via unspecified vectors, as demonstrated by an internationalized domain name to ping6.
Exploitability
AV:NAC:HAu:NImpact
C:PI:PA:P5.1/AV:N/AC:H/Au:N/C:P/I:P/A:P