Securing Your Web Application: How to Fix a Vulnerability in Symfony HTTP Cache Component

Introduction

In this article we’ll talk about a recent vulnerability found in the Symfony HTTP cache component ( symfony/http-kernel ), how it may affect you and how to fix it.

Check if it impacts you

First of all, it’s important to find out if you are affected by the vulnerability, so you should check that you use symfony/http-kernel package in your project and if the package version is between one of the following ranges: >= 2.0.0, < 4.4.50, >= 5.0.0, < 5.4.20, >= 6.0.0, < 6.0.20, >= 6.1.0, < 6.1.12, >= 6.2.0, < 6.2.6.

You can easily use composer to find-out the version you use:

composer show symfony/http-kernel  | grep versions

If you get an error saying that the package is not found or the version is not in the ranges above, you are safe, so you can skip the rest of the article ( if you’re not curious about the impact of the vulnerability of course 😊 ).

In the sad case you are affected, the next step is to check if you use http cache reverse proxy supplied by the symfony framework. To do so, you should navigate to config/packages/framework.yaml and check if you have http_cache flag set to true. You can read more…