Mpdude

**Name of the Vulnerable Software and Affected Versions** Symfony versions prior to 4.4.13 Symfony versions prior to 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, where all HTTP calls come from a trusted backend. However, 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. **Recommendations** For Symfony versions prior to 4.4.13, update to version 4.4.13 or later. For Symfony versions prior to 5.1.5, update to version 5.1.5 or later. As a temporary workaround, consider stripping HTTP headers designed for internal use in `HttpCache` from remote responses before being passed to `HttpCache`.