The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) 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.
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "2.6.3+dfsg1-1", "binary_name": "ruby-mail" } ] }