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GHSA-fqc7-9xjw-jrh3

SymfonyRuntime CVE-2024-50340 Patch Bypass: Web Requests Can Still Set APP_ENV/APP_DEBUG via parse_str/SAPI Argv Mismatch

Source: GitHub Advisory Database (reviewed) Moderate CVE-2026-47767

Packages

EcosystemPackageAffectedFixed in
Packagist symfony/runtime >= 5.4.46, < 5.4.52 5.4.52
Packagist symfony/runtime >= 6.4.14, < 6.4.40 6.4.40
Packagist symfony/runtime >= 7.1.7, < 7.4.12 7.4.12
Packagist symfony/runtime >= 8.0.0, < 8.0.12 8.0.12
Packagist symfony/symfony >= 5.4.46, < 5.4.52 5.4.52
Packagist symfony/symfony >= 6.4.14, < 6.4.40 6.4.40
Packagist symfony/symfony >= 7.1.7, < 7.4.12 7.4.12
Packagist symfony/symfony >= 8.0.0, < 8.0.12 8.0.12

Details

As written in the advisory (Markdown source, shown as plain text).

### 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://github.com/symfony/symfony/commit/3228c3806ee511008bea19a95084d460b17e5d25) for branch 5.4. ### Credits SymfonyRuntime would like to thank 0xEr3n for reporting the issue and Nicolas Grekas for providing the fix.

References

External links from the advisory. They lead to third-party sites.