Headline
CVE-2022-24894: [HttpKernel] Remove private headers before storing responses with Htt… · symfony/symfony@d2f6322
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The Symfony HTTP cache system, acts as a reverse proxy: It caches entire responses (including headers) and returns them to the clients. In a recent change in the AbstractSessionListener, the response might contain a Set-Cookie header. If the Symfony HTTP cache system is enabled, this response might bill stored and return to the next clients. An attacker can use this vulnerability to retrieve the victim’s session. This issue has been patched and is available for branch 4.4.
@@ -26,19 +26,29 @@ class Store implements StoreInterface { protected $root; private $keyCache; private $locks; private $locks = []; private $options;
/** * Constructor. * * The available options are: * * * private_headers Set of response headers that should not be stored * when a response is cached. (default: Set-Cookie) * * @throws \RuntimeException */ public function __construct(string $root) public function __construct(string $root, array $options = []) { $this->root = $root; if (!file_exists($this->root) && !@mkdir($this->root, 0777, true) && !is_dir($this->root)) { throw new \RuntimeException(sprintf('Unable to create the store directory (%s).’, $this->root)); } $this->keyCache = new \SplObjectStorage(); $this->locks = []; $this->options = array_merge([ ‘private_headers’ => [‘Set-Cookie’], ], $options); }
/** @@ -215,6 +225,10 @@ public function write(Request $request, Response $response) $headers = $this->persistResponse($response); unset($headers[‘age’]);
foreach ($this->options[‘private_headers’] as $h) { unset($headers[strtolower($h)]); }
array_unshift($entries, [$storedEnv, $headers]);
if (!$this->save($key, serialize($entries))) {
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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.