CVE-2023-34252
Grav is a flat-file content management system. Prior to version 1.7.42, there is a logic flaw in the `GravExtension.filterFilter()` function whereby validation against a denylist of unsafe functions is only performed when the argument passed to filter is a string. However, passing an array as a callable argument allows the validation check to be skipped. Consequently, a low privileged attacker with login access to Grav Admin panel and page creation/update permissions is able to inject malicious templates to obtain remote code execution.
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The vulnerability can be found in the `GravExtension.filterFilter()` function declared in `/system/src/Grav/Common/Twig/Extension/GravExtension.php`. Version 1.7.42 contains a patch for this issue. End users should also ensure that `twig.undefined_functions` and `twig.undefined_filters` properties in `/path/to/webroot/system/config/system.yaml` configuration file are set to `false` to disallow Twig from treating undefined filters/functions as PHP functions and executing them.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.2
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 2.07%
- Percentil entre todas las CVEs puntuadas: 81
- Fecha de la puntuación: 7/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-184, CWE-1336
- CWE-94
Referencias
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074
- https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec
- https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074
- https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec
- https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w
JSON original (NVD)
Mostrar
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