CVE-2022-24790

Puma is a simple, fast, multi-threaded, parallel HTTP 1.1 server for Ruby/Rack applications. When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend proxy may disagree on where a request starts and ends. This would allow requests to be smuggled via the front-end proxy to Puma. The vulnerability has been fixed in 5.6.4 and 4.3.12. Users are advised to upgrade as soon as possible. Workaround: when deploying a proxy in front of Puma, turning on any and all functionality to make sure that the request matches the RFC7230 standard.

When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend proxy may disagree on where a request starts and ends. This would allow requests to be smuggled via the front-end proxy to Puma. The following vulnerabilities are addressed by this advisory: - Lenient parsing of `Transfer-Encoding` headers, when unsupported encodings should be rejected and the final encoding must be `chunked`. - Lenient parsing of malformed `Content-Length` headers and chunk sizes, when only digits and hex digits should be allowed. - Lenient parsing of duplicate `Content-Length` headers, when they should be rejected. - Lenient parsing of the ending of chunked segments, when they should end with `\r\n`. The vulnerability has been fixed in 5.6.4 and 4.3.12. When deploying a proxy in front of Puma, turning on any and all functionality to make sure that the request matches the RFC7230 standard. These proxy servers are known to have "good" behavior re: this standard and upgrading Puma may not be necessary. Users are encouraged to validate for themselves. - Nginx (latest) - Apache (latest) - Haproxy 2.5+ - Caddy (latest) - Traefik (latest)

When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend proxy may disagree on where a request starts and ends. This would allow requests to be smuggled via the front-end proxy to Puma. The following vulnerabilities are addressed by this advisory: - Lenient parsing of `Transfer-Encoding` headers, when unsupported encodings should be rejected and the final encoding must be `chunked`. - Lenient parsing of malformed `Content-Length` headers and chunk sizes, when only digits and hex digits should be allowed. - Lenient parsing of duplicate `Content-Length` headers, when they should be rejected. - Lenient parsing of the ending of chunked segments, when they should end with `\r\n`. The vulnerability has been fixed in 5.6.4 and 4.3.12. When deploying a proxy in front of Puma, turning on any and all functionality to make sure that the request matches the RFC7230 standard. These proxy servers are known to have "good" behavior re: this standard and upgrading Puma may not be necessary. Users are encouraged to validate for themselves. - Nginx (latest) - Apache (latest) - Haproxy 2.5+ - Caddy (latest) - Traefik (latest)

Puma es un servidor HTTP versión 1.1 simple, rápido, multihilo y paralelo para aplicaciones Ruby/Rack. Cuando es usado Puma detrás de un proxy que no comprueba apropiadamente que la petición HTTP entrante coincide con el estándar RFC7230, Puma y el proxy del frontend pueden no estar de acuerdo en dónde empieza y termina una petición. Esto permitiría contrabandear peticiones por medio del proxy del front-end a Puma. La vulnerabilidad ha sido corregida en versiones 5.6.4 y 4.3.12. Se recomienda a usuarios actualizar lo antes posible. Mitigación: cuando despliegue un proxy frente a Puma, habilite todas las funciones para asegurarse de que la petición se ajusta al estándar RFC7230