GHSA-h7vf-5wrv-9fhv

Symfony storing cookie headers in HttpCache

Description ----------- The Symfony HTTP cache system acts as a reverse proxy: it caches HTTP responses (including headers) and returns them to clients. In a recent `AbstractSessionListener` change, the response might now contain a `Set-Cookie` header. If the Symfony HTTP cache system is enabled, this header might be stored and returned to some other clients. An attacker can use this vulnerability to retrieve the victim's session. Resolution ---------- The `HttpStore` constructor now takes a parameter containing a list of private headers that are removed from the HTTP response headers. The default value for this parameter is `Set-Cookie`, but it can be overridden or extended by the application. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/d2f6322af9444ac5cd1ef3ac6f280dbef7f9d1fb) for branch 4.4. Credits ------- We would like to thank Soner Sayakci for reporting the issue and Nicolas Grekas for fixing it.