acpid.c in acpid before 2.0.9 does not properly handle a situation in which a process has connected to acpid.socket but is not reading any data, which allows local users to cause a denial of service (daemon hang) via a crafted application that performs a connect system call but no read system calls.
https://bugzilla.redhat.com/show_bug.cgi?id=688698
http://www.securityfocus.com/bid/45915
http://secunia.com/advisories/44621
http://secunia.com/advisories/42947
http://lists.fedoraproject.org/pipermail/package-announce/2011-May/060053.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-May/059880.html