The MITRE CVE dictionary describes this issue as:
The host_reliable_addrinfo function in support/export/hostname.c in nfs-utils before 1.2.4 does not properly use DNS to verify access to NFS exports, which allows remote attackers to mount filesystems by establishing crafted DNS A and PTR records.
Find out more about CVE-2011-2500 from the
MITRE CVE dictionary dictionary and
This issue did not affect the versions of nfs-utils as shipped with Red Hat Enterprise Linux 4 and 5. The Red Hat Security Response Team has rated this issue as having low security impact; a future update in Red Hat Enterprise Linux 6 may address this flaw.