CVE-2020-5255

In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.

In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.

Description ----------- When a `Response` does not contain a `Content-Type` header, Symfony falls back to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can lead to a corrupted cache where the cached format is not the right one. Resolution ---------- Symfony does not use the `Accept` header anymore to guess the `Content-Type`. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6) for the 4.4 branch. Credits ------- I would like to thank Xavier Lacot from JoliCode for reporting & Yonel Ceruto and Tobias Schultze for fixing the issue.

Description ----------- When a `Response` does not contain a `Content-Type` header, Symfony falls back to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can lead to a corrupted cache where the cached format is not the right one. Resolution ---------- Symfony does not use the `Accept` header anymore to guess the `Content-Type`. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6) for the 4.4 branch. Credits ------- I would like to thank Xavier Lacot from JoliCode for reporting & Yonel Ceruto and Tobias Schultze for fixing the issue.

En Symfony en versiones anteriores a las versiones 4.4.7 y 5.0.7, cuando una "Response" no contiene un encabezado "Content-Type", las versiones afectadas de Symfony pueden retroceder al formato definido en el encabezado "Accept" de la petición, conllevando a una posible falta de coincidencia entre el contenido response's y el encabezado "Content-Type". Cuando la respuesta es almacenada en caché, esto puede impedir el uso del sitio web por otros usuarios. Esto ha sido parcheado en las versiones 4.4.7 y 5.0.7.