Symptoms
A stack-based buffer overflow was found in libresolv in the code which performs dual A/AAAA DNS queries. A remote attacker could create specially crafted DNS responses which could cause libresolv to crash or potentially execute code with the permissions of the user running the library.
This issue has been rated as having Critical impact by Red Hat Product Security.
This issue did not affect the version of glibc shipped with Red Hat Enterprise Linux 5 or earlier. This issue affected the versions of glibc shipped with Red Hat Enterprise Linux 6 and 7.
Read more details on RedHat site
Resolution
Operation System Vendors already released corresponding updates for the glibc library, please update your OS following standard procedure as soon as possible: