It was reported  that getnetbyname function in glibc 2.21 in earlier will enter an infinite loop if the DNS backend is activated in the system Name Service Switch configuration, and the DNS resolver receives a positive answer while processing the network name.
Upstream commit that fixes this issue:
Created glibc tracking bugs for this issue:
Affects: fedora-all [bug 1175370]
MITRE assigned CVE-2014-9402 to this issue:
A non-standard system configuration ("networks: file dns" in /etc/nsswitch.conf) and possibly a DNS spoofing attack is required to exploit this flaw.
Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2018:0805 https://access.redhat.com/errata/RHSA-2018:0805