Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:9 relevant versions.
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.
ruby2.3 to version 2.3.3-1+deb9u3 or higher.