A serious vulnerability has been discovered in two legacy functions that are related to DNS resolution in glibc. Due to the fact that glibc is a fundamental OS component used by many pieces of "userland" software, this vulnerability is a high priority for remediation.
Background (From the CVE Project)
There is a heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and other 2.x versions before 2.18. This allows context-dependent attackers to execute arbitrary code via vectors related to the (1) gethostbyname or (2) gethostbyname2 function, aka "GHOST.”
10 (from NVD/NIST)
Additional information and product vulnerability status can be found here:
The above linked PDF will be updated as we receive more information.