Ruby is vulnerable to information disclosure attacks. This is because of the way String#unpack decodes the unpacking format. An attacker could use this flaw to control the unpack format which leads to disclose arbitrary parts of the application’s memory.
lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html
www.securityfocus.com/bid/103693
www.securitytracker.com/id/1042004
access.redhat.com/errata/RHSA-2018:3729
access.redhat.com/errata/RHSA-2018:3730
access.redhat.com/errata/RHSA-2018:3731
access.redhat.com/errata/RHSA-2019:2028
access.redhat.com/security/updates/classification/#important
bugzilla.redhat.com/show_bug.cgi?id=1650591
lists.debian.org/debian-lts-announce/2018/04/msg00023.html
lists.debian.org/debian-lts-announce/2018/04/msg00024.html
lists.debian.org/debian-lts-announce/2018/07/msg00012.html
usn.ubuntu.com/3626-1/
www.debian.org/security/2018/dsa-4259
www.ruby-lang.org/en/news/2018/03/28/buffer-under-read-unpack-cve-2018-8778/
www.ruby-lang.org/en/news/2018/03/28/ruby-2-2-10-released/
www.ruby-lang.org/en/news/2018/03/28/ruby-2-3-7-released/
www.ruby-lang.org/en/news/2018/03/28/ruby-2-4-4-released/
www.ruby-lang.org/en/news/2018/03/28/ruby-2-5-1-released/