A ruby-rack-cors security update has been released for Debian GNU/Linux 8 LTS to address an issue with directory traversal to access private resources.

Package : ruby-rack-cors
Version : 0.2.9-1+deb8u1
CVE ID : CVE-2019-18978

This package allowed ../ directory traversal to access private resources
because resource matching did not ensure that pathnames were in a canonical
format.

For Debian 8 "Jessie", this problem has been fixed in version
0.2.9-1+deb8u1.

We recommend that you upgrade your ruby-rack-cors packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS