Net::SMTP in Ruby before 2.4.0 is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substring.
https://hackerone.com/reports/137631
https://github.com/rubysec/ruby-advisory-db/issues/215
https://github.com/ruby/ruby/commit/0827a7e52ba3d957a634b063bf5a391239b9ffee
https://www.debian.org/security/2017/dsa-3966
https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
Source: Mitre, NVD
Published: 2017-06-12
Updated: 2025-04-20
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.00998