A memory leak in rsyslog before 5.7.6 was found in the way deamon processed log messages were logged when multiple rulesets were used and some output batches contained messages belonging to more than one ruleset. A local attacker could cause denial of the rsyslogd daemon service via a log message belonging to more than one ruleset.
https://security-tracker.debian.org/tracker/CVE-2011-1489
https://github.com/rsyslog/rsyslog/commit/1ef709cc97d54f74d3fdeb83788cc4b01f4c6a2a
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-1489
http://lists.opensuse.org/opensuse-security-announce/2011-04/msg00005.html