Balabit syslog-ng allows remote attackers to cause a denial of service (application crash) via a malformed log message that does not have a closing > in the priority specifier.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5576
http://www.balabit.hu/products/syslog-ng/
http://archives.neohapsis.com/archives/bugtraq/2000-11/0300.html