Rack is a modular Ruby web server interface. The Rack::Sendfile middleware logs unsanitised header values from the X-Sendfile-Type header. An attacker can exploit this by injecting escape sequences (such as newline characters) into the header, resulting in log injection. This vulnerability is fixed in 2.2.12, 3.0.13, and 3.1.11.
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 |
|---|---|---|---|
| Rack | Rack | * | 2.2.12 (excluding) |
| Rack | Rack | 3.0.0 (including) | 3.0.13 (excluding) |
| Rack | Rack | 3.1.0 (including) | 3.1.11 (excluding) |
| Ruby-rack | Ubuntu | devel | * |
| Ruby-rack | Ubuntu | esm-apps/bionic | * |
| Ruby-rack | Ubuntu | esm-apps/focal | * |
| Ruby-rack | Ubuntu | esm-apps/jammy | * |
| Ruby-rack | Ubuntu | esm-apps/xenial | * |
| Ruby-rack | Ubuntu | esm-infra-legacy/trusty | * |
| Ruby-rack | Ubuntu | focal | * |
| Ruby-rack | Ubuntu | jammy | * |
| Ruby-rack | Ubuntu | noble | * |
| Ruby-rack | Ubuntu | oracular | * |
| Ruby-rack | Ubuntu | plucky | * |
| Ruby-rack | Ubuntu | questing | * |
| Ruby-rack | Ubuntu | upstream | * |
Potential Mitigations
Related Attack Patterns
References
- https://github.com/rack/rack/commit/803aa221e8302719715e224f4476e438f2531a53
- https://github.com/rack/rack/commit/aeac570bb8080ca7b53b7f2e2f67498be7ebd30b
- https://github.com/rack/rack/commit/b13bc6bfc7506aca3478dc5ac1c2ec6fc53f82a3
- https://github.com/rack/rack/security/advisories/GHSA-8cgq-6mh2-7j6v
- https://lists.debian.org/debian-lts-announce/2025/03/msg00016.html