The client logging functionality in chronyd in Chrony before 1.23.1 does not restrict the amount of memory used for storage of client information, which allows remote attackers to cause a denial of service (memory consumption) via spoofed (1) NTP or (2) cmdmon packets.
chrony.tuxfamily.org/News.html
git.tuxfamily.org/chrony/chrony.git/?p=gitroot/chrony/chrony.git%3Ba=commit%3Bh=2f63cf448560fdb96b80d8488aae6a15b802a753
secunia.com/advisories/38428
secunia.com/advisories/38480
www.debian.org/security/2010/dsa-1992
www.securityfocus.com/bid/38106
bugzilla.redhat.com/show_bug.cgi?id=555367