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.
{ "nvd_published_at": null, "cwe_ids": [ "CWE-93" ], "severity": "MODERATE", "github_reviewed": true, "github_reviewed_at": "2020-06-16T21:51:27Z" }