Buffer overflows in BSD-based FTP servers allows remote attackers to execute arbitrary commands via a long pattern string containing a {} sequence, as seen in (1) g_opendir, (2) g_lstat, (3) g_stat, and (4) the glob0 buffer as used in the glob functions glob2 and glob3.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6332
http://www.nai.com/research/covert/advisories/048.asp
http://www.cert.org/advisories/CA-2001-07.html
http://archives.neohapsis.com/archives/freebsd/2001-04/0466.html