CVE-2020-15094

In Symfony before versions 4.4.13 and 5.1.5, the CachingHttpClient class from the HttpClient Symfony component relies on the HttpCache class to handle requests. HttpCache uses internal headers like X-Body-Eval and X-Body-File to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by CachingHttpClient and if an attacker can control the response for a request being made by the CachingHttpClient, remote code execution is possible. This has been fixed in versions 4.4.13 and 5.1.5.

In Symfony before versions 4.4.13 and 5.1.5, the CachingHttpClient class from the HttpClient Symfony component relies on the HttpCache class to handle requests. HttpCache uses internal headers like X-Body-Eval and X-Body-File to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by CachingHttpClient and if an attacker can control the response for a request being made by the CachingHttpClient, remote code execution is possible. This has been fixed in versions 4.4.13 and 5.1.5.

Description ----------- The `CachingHttpClient` class from the HttpClient Symfony component relies on the `HttpCache` class to handle requests. `HttpCache` uses internal headers like `X-Body-Eval` and `X-Body-File` to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by `CachingHttpClient` and if an attacker can control the response for a request being made by the `CachingHttpClient`, remote code execution is possible. Resolution ---------- HTTP headers designed for internal use in `HttpCache` are now stripped from remote responses before being passed to `HttpCache`. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/d9910e0b33a2e0f993abff41c6fbc86951b66d78) for the 4.4 branch. Credits ------- I would like to thank Matthias Pigulla (webfactory GmbH) for reporting and fixing the issue.

Description ----------- The `CachingHttpClient` class from the HttpClient Symfony component relies on the `HttpCache` class to handle requests. `HttpCache` uses internal headers like `X-Body-Eval` and `X-Body-File` to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by `CachingHttpClient` and if an attacker can control the response for a request being made by the `CachingHttpClient`, remote code execution is possible. Resolution ---------- HTTP headers designed for internal use in `HttpCache` are now stripped from remote responses before being passed to `HttpCache`. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/d9910e0b33a2e0f993abff41c6fbc86951b66d78) for the 4.4 branch. Credits ------- I would like to thank Matthias Pigulla (webfactory GmbH) for reporting and fixing the issue.

En Symfony versiones anteriores a 4.4.13 y 5.1.5, la clase CachingHttpClient del componente HttpClient Symfony se basa en la clase HttpCache para manejar las peticiones. HttpCache utiliza encabezados internos como X-Body-Eval y X-Body-File para controlar la restauración de las respuestas almacenadas en caché. La clase fue inicialmente escrita teniendo en cuenta el almacenamiento en caché sustituto y la compatibilidad con ESI (todas las llamadas HTTP provienen de un backend confiable en ese escenario). Pero cuando es usado por CachingHttpClient y si un atacante puede controlar la respuesta para una petición siendo hecha por CachingHttpClient, es posible una ejecución de código remota. Esto ha sido corregido en las versiones 4.4.13 y 5.1.5