The wait_for_child_to_die function in main/event.c in FreeRADIUS 2.1.x before 2.1.10, in certain circumstances involving long-term database outages, does not properly handle long queue times for requests, which allows remote attackers to cause a denial of service (daemon crash) by sending many requests.
https://bugzilla.redhat.com/show_bug.cgi?id=639397
https://bugs.freeradius.org/bugzilla/show_bug.cgi?id=35
http://www.openwall.com/lists/oss-security/2010/10/01/8
http://www.openwall.com/lists/oss-security/2010/10/01/3
http://secunia.com/advisories/41621
http://github.com/alandekok/freeradius-server/commit/ff94dd35673bba1476594299d31ce8293b8bd223