lib/logmatcher.c in Balabit syslog-ng before 3.2.4, when the global flag is set and when using PCRE 8.12 and possibly other versions, allows remote attackers to cause a denial of service (memory consumption) via a message that does not match a regular expression.
git.balabit.hu/?p=bazsi/syslog-ng-3.2.git%3Ba=commit%3Bh=09710c0b105e579d35c7b5f6c66d1ea5e3a3d3ff
lists.fedoraproject.org/pipermail/package-announce/2011-June/062107.html
secunia.com/advisories/45122
www.openwall.com/lists/oss-security/2011/05/26/1
www.securityfocus.com/bid/47800
bugzilla.redhat.com/show_bug.cgi?id=709088