The remote_cmds component in Apple Mac OS X 10.4 through 10.4.10 contains a symbolic link from the tftpboot private directory to the root directory, which allows tftpd users to escape the private directory and access arbitrary files.
https://exchange.xforce.ibmcloud.com/vulnerabilities/38471
http://www.vupen.com/english/advisories/2007/3868
http://www.us-cert.gov/cas/techalerts/TA07-319A.html
http://www.securityfocus.com/bid/26444
http://securitytracker.com/id?1018950
http://secunia.com/advisories/27643
http://lists.apple.com/archives/security-announce/2007/Nov/msg00002.html