The lazy_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demonstrated by a Resolv::Hosts::new argument beginning with a '|' character, a different vulnerability than CVE-2017-17405. NOTE: situations with untrusted input may be highly unlikely.
https://access.redhat.com/errata/RHSA-2018:0378
https://access.redhat.com/errata/RHSA-2018:0583
https://access.redhat.com/errata/RHSA-2018:0584
https://access.redhat.com/errata/RHSA-2018:0585
https://github.com/ruby/ruby/pull/1777
https://lists.debian.org/debian-lts-announce/2017/12/msg00024.html
https://lists.debian.org/debian-lts-announce/2017/12/msg00025.html
https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
Source: MITRE
Published: 2017-12-20
Updated: 2018-08-03
Type: CWE-74
Base Score: 7.5
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 10
Severity: HIGH
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 3.9
Severity: CRITICAL