The glibc packages provide the standard C libraries , POSIX thread libraries , standard math libraries , and the name service cache daemon used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly. Security Fix: * A stack overflow vulnerability was found in _nss_dns_getnetbyname_r. On systems with nsswitch configured to include "networks: dns" with a privileged or network-facing service that would attempt to resolve user-provided network names, an attacker could provide an excessively long network name, resulting in stack corruption and code execution. This issue was discovered by Florian Weimer . Additional Changes: For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.