Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 5.4.46 until 5.4.52, 6.4.40, 7.4.12, and 8.0.12, the CVE-2024-50340 fix gated runtime argv parsing on empty($_GET), but parse_str() and the web SAPI can disagree, allowing a crafted query string to leave $_GET empty while $_SERVER['argv'] still carries attacker-controlled --env or --no-debug flags that change APP_ENV or APP_DEBUG. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Affected: Packagist: symfony/runtime, Packagist: symfony/symfony

### Description

CVE-2024-50340 (GHSA-x8vp-gf4q-mw5j) addressed an issue where, with `register_argc_argv=On`, a crafted query string let an unauthenticated GET change the kernel environment and debug flag by feeding `--env`/`--no-debug` through `$_SERVER['argv']`. The fix shipped in `symfony/runtime` 5.4.46 / 6.4.14 / 7.1.7 gated the argv read on `empty($_GET)` as a proxy for "is this a CLI invocation".

That proxy is unsafe: `parse_str()` (which builds `$_GET`) and the web SAPI (which builds `$_SERVER['argv']` from the raw query when `register_argc_argv=On`) do not agree on every input, so an attacker can craft a query that leaves `$_GET` empty while `$_SERVER['argv']` carries the attacker's flags. `SymfonyRuntime::getInput()` then parses them, restoring the exact primitive CVE-2024-50340 was meant to prevent.

Preconditions and impact match the original CVE: web SAPI, `register_argc_argv=On`, app booted through `symfony/runtime`; from an unauthenticated GET an attacker can flip `APP_ENV` and toggle `APP_DEBUG`.

### Resolution

`SymfonyRuntime` now gates the argv read on `isset($_SERVER['QUERY_STRING'])` rather than on `empty($_GET)`. `QUERY_STRING` is the same input the SAPI uses to build argv, so the security check and the thing it protects no longer parse different sources. Worker SAPIs (FrankenPHP / RoadRunner / Swoole) keep working because the runtime constructor runs once at boot when `QUERY_STRING` is unset.

The patch for this issue is available [here](https://gith…

Affected: Ubuntu:16.04:LTS: symfony, Ubuntu:Pro:18.04:LTS: symfony, Ubuntu:Pro:20.04:LTS: symfony, Ubuntu:Pro:22.04:LTS: symfony, Ubuntu:Pro:24.04:LTS: symfony, Ubuntu:26.04:LTS: symfony

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 5.4.46 until 5.4.52, 6.4.40, 7.4.12, and 8.0.12, the CVE-2024-50340 fix gated runtime argv parsing on empty($_GET), but parse_str() and the web SAPI can disagree, allowing a crafted query string to leave $_GET empty while $_SERVER['argv'] still carries attacker-controlled --env or --no-debug flags that change APP_ENV or APP_DEBUG. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.