The FTP wildcard function in curl and libcurl before 7.57.0 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) or possibly have unspecified other impact via a string that ends with an '[' character.
https://www.debian.org/security/2017/dsa-4051
https://security.gentoo.org/glsa/201712-04
https://lists.debian.org/debian-lts-announce/2017/11/msg00040.html
https://curl.haxx.se/docs/adv_2017-ae72.html
https://access.redhat.com/errata/RHSA-2018:3558
http://www.securitytracker.com/id/1039897
http://www.securityfocus.com/bid/102057
http://security.cucumberlinux.com/security/details.php?id=162