Investigations showed that the issue affected all the versions of #glibc since 2.9. You should definitely update if you are on an older version though. If the #vulnerability is detected, machine owners may wish to take steps to mitigate the risk of an attack.
The glibc #DNS client side resolver is vulnerable to a stack-based buffer overflow when the getaddrinfo() library function is used. Software using this function may be exploited with attacker-controlled domain names, attacker-controlled DNS servers, or through a man-in-the-middle attack.
More information: http://s.ibscc.net/5JDie