CVE 2017-7418
ProFTPD before 1.3.5e and 1.3.6 before 1.3.6rc5 controls whether the home directory of a user could contain a symbolic link through the AllowChrootSymlinks configuration option, but checks only the last path component when enforcing AllowChrootSyml
See the
CVE page on Mitre.org
for more details.