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

For Debian 9 stretch, this problem has been fixed in version 0.4.0-1+deb9u2.

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

For the detailed security status of ruby-rack-cors please refer to its security tracker page at: https://security-tracker.debian.org/tracker/ruby-rack-cors

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