Critical (9.8) in ruby-lang ruby. EPSS 5.9% chance of exploitation in the next 30 days.
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.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
5.9% chance of exploitation in the next 30 days; higher than 93% of CVEs (scores of 2026-10-31)