event.c in acpid (aka acpid2) before 2.0.11 does not have an appropriate umask setting during execution of event-handler scripts, which might allow local users to (1) perform write operations within directories created by a script, or (2) read files created by a script, via standard filesystem system calls.
sourceforge.net/u/tedfelix/acpid2/ci/02d0bf29207f17996936ab652717855b15873901/tree/Changelog?force=True
www.mandriva.com/security/advisories?name=MDVSA-2012:138
www.openwall.com/lists/oss-security/2011/12/06/3
bugs.launchpad.net/ubuntu/+source/acpid/+bug/893821
bugzilla.redhat.com/show_bug.cgi?id=760984