Memory leak in a certain Red Hat patch, applied to vsftpd 2.0.5 on Red Hat Enterprise Linux (RHEL) 5 and Fedora 6 through 8, and on Foresight Linux and rPath appliances, allows remote attackers to cause a denial of service (memory consumption) via a large number of CWD commands, as demonstrated by an attack on a daemon with the deny_file configuration option.