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.
Weakness
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ruby | Ruby-lang | * | 2.4.0 (including) |
| Ruby1.9.1 | Ubuntu | trusty | * |
| Ruby1.9.1 | Ubuntu | upstream | * |
| Ruby2.0 | Ubuntu | trusty | * |
| Ruby2.0 | Ubuntu | upstream | * |
| Ruby2.3 | Ubuntu | devel | * |
| Ruby2.3 | Ubuntu | esm-infra/xenial | * |
| Ruby2.3 | Ubuntu | upstream | * |
| Ruby2.3 | Ubuntu | xenial | * |
| Ruby2.3 | Ubuntu | yakkety | * |
| Ruby2.3 | Ubuntu | zesty | * |
Potential Mitigations
Related Attack Patterns
References
- http://www.mbsd.jp/Whitepaper/smtpi.pdf
- https://github.com/ruby/ruby/commit/0827a7e52ba3d957a634b063bf5a391239b9ffee
- https://github.com/rubysec/ruby-advisory-db/issues/215
- https://hackerone.com/reports/137631
- https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
- https://www.debian.org/security/2017/dsa-3966
- http://www.mbsd.jp/Whitepaper/smtpi.pdf
- https://github.com/ruby/ruby/commit/0827a7e52ba3d957a634b063bf5a391239b9ffee
- https://github.com/rubysec/ruby-advisory-db/issues/215
- https://hackerone.com/reports/137631
- https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
- https://www.debian.org/security/2017/dsa-3966