bug #42637 [Security] Fixed TOCTOU in RememberMe cache token verifier

Ivan Kurnosov · Ivan Kurnosov · commit 2b8bee5fd17d · 2022-03-22T21:15:34.000+13:00
diff --git a/src/Symfony/Component/Security/Core/Authentication/RememberMe/CacheTokenVerifier.php b/src/Symfony/Component/Security/Core/Authentication/RememberMe/CacheTokenVerifier.php
@@ -45,12 +45,12 @@ public function verifyToken(PersistentTokenInterface $token, string $tokenValue)
         }
 
         $cacheKey = $this->getCacheKey($token);
-        if (!$this->cache->hasItem($cacheKey)) {
-            return false;
-        }
-
         $item = $this->cache->getItem($cacheKey);
+
         $outdatedToken = $item->get();
+        if (!\is_string($outdatedToken)) {
+            return false;
+        }
 
         return hash_equals($outdatedToken, $tokenValue);
     }
