Time-of-check Time-of-use (TOCTOU) Race Condition in league/flysystem
Impact
The whitespace normalisation using in 1.x and 2.x removes any unicode whitespace. Under certain specific conditions this could potentially allow a malicious user to execute code remotely.
The conditions:
- A user is allowed to supply the path or filename of an uploaded file.
- The supplied path or filename is not checked against unicode chars.
- The supplied pathname checked against an extension deny-list, not an allow-list.
- The supplied path or filename contains a unicode whitespace char in the extension.
- The uploaded file is stored in a directory that allows PHP code to be executed.
Given these conditions are met a user can upload and execute arbitrary code on the system under attack.
Patches
The unicode whitespace removal has been replaced with a rejection (exception).
The library has been patched in:
- 1.x: https://github.com/thephpleague/flysystem/commit/f3ad69181b8afed2c9edf7be5a2918144ff4ea32
- 2.x: https://github.com/thephpleague/flysystem/commit/a3c694de9f7e844b76f9d1b61296ebf6e8d89d74
Workarounds
For 1.x users, upgrade to 1.1.4. For 2.x users, upgrade to 2.1.1.
Software afectado
Haz clic en una tecnología para ver todas sus vulnerabilidades.
| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de Composer | league/flysystem | < 1.1.4, >= 2.0.0, < 2.1.1 | 1.1.4, 2.1.1 |
Referencias
- https://github.com/thephpleague/flysystem/security/advisories/GHSA-9f46-5r25-5wfm
- https://nvd.nist.gov/vuln/detail/CVE-2021-32708
- https://github.com/thephpleague/flysystem/commit/a3c694de9f7e844b76f9d1b61296ebf6e8d89d74
- https://github.com/thephpleague/flysystem/commit/f3ad69181b8afed2c9edf7be5a2918144ff4ea32
- https://github.com/FriendsOfPHP/security-advisories/blob/master/league/flysystem/CVE-2021-32708.yaml
- https://github.com/thephpleague/flysystem
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NWPTENBYKI2IG47GI4DHAACLNRLTWUR5
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RNZSWK4GOMJOOHKLZEOE5AQSLC4DNCRZ
- https://packagist.org/packages/league/flysystem
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Debilidad (CWE)
CWE-367- Plataforma
- Composer
- Paquete
league/flysystem- Publicada
- 29.06.2021
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-9f46-5r25-5wfm - CC BY 4.0
Historial de vulnerabilidades: league/flysystem
Todas las vulnerabilidades publicadas de este paquete (Paquete de Composer), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 2
- Primera → última
- 06.2021 09.2026
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 1
- Baja 1
Divulgaciones por año
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 1
-
Time-of-check Time-of-use (TOCTOU) Race Condition in league/flysystem esta entrada
Identifica las vulnerabilidades de tu aplicación
Con la integración de DockRay y el inventario de software activado, DockRay compara las versiones notificadas de los componentes con las vulnerabilidades conocidas y avisa de las coincidencias confirmadas. La cobertura depende de la tecnología compatible y de los avisos disponibles.