{"id":"CVE-2023-34252","summary":"Grav Server-side Template Injection via Insufficient Validation in filterFilter","details":"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. 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.","aliases":["GHSA-96xv-rmwj-6p9w"],"modified":"2026-08-12T03:51:32.894656310Z","published":"2023-06-14T21:38:48.358Z","database_specific":{"cwe_ids":["CWE-1336","CWE-184"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/34xxx/CVE-2023-34252.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698"},{"type":"WEB","url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/34xxx/CVE-2023-34252.json"},{"type":"ADVISORY","url":"https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-34252"},{"type":"FIX","url":"https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/getgrav/grav","events":[{"introduced":"0"},{"fixed":"dc209453d0817547db0d3a8b27110decb63f2b5d"},{"fixed":"244758d4383034fe4cd292d41e477177870b65ec"}],"database_specific":{"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.7.42"}]}}],"versions":["1.7.41.2","1.7.41.1","1.7.41","1.7.40","1.7.39.4","1.7.39.3","1.7.39.2","1.7.39.1","1.7.39","1.7.38","1.7.37.1","1.7.37","1.7.36","1.7.35","1.7.34","1.7.33","1.7.32","1.7.31","1.7.30","1.7.29.1","1.7.29","1.7.28","1.7.27.1","1.7.27","1.7.26.1","1.7.26","1.7.25","1.7.24","1.7.23","1.7.22","1.7.21","1.7.20","1.7.19","1.7.18","1.7.17","1.7.16","1.7.15","1.7.14","1.7.13","1.7.12","1.7.10","1.7.9","1.7.8","1.7.7","1.7.6","1.7.5","1.7.4","1.7.3","1.7.1","1.7.0","1.7.0-rc.20","1.7.0-rc.19","1.7.0-rc.18","1.7.0-rc.17","1.7.0-rc.15","1.7.0-rc.14","1.7.0-rc.13","1.7.0-rc.12","1.7.0-rc.10","1.7.0-rc.9","1.7.0-rc.8","1.7.0-rc.7","1.7.0-rc.6","1.7.0-rc.5","1.7.0-rc.4","1.7.0-rc.3","1.7.0-rc.2","1.7.0-rc.1","1.7.0-beta.10","1.7.0-beta.9","1.7.0-beta.8","1.7.0-beta.7","1.7.0-beta.6","1.7.0-beta.5","1.7.0-beta.4","1.7.0-beta.3","1.7.0-beta.2","1.7.0-beta.1","1.6.0-rc.4","1.6.0-rc.3","1.6.0-rc.2","1.6.0-rc.1","1.6.0-beta.8","1.6.0-beta.7","1.6.0-beta.6","1.6.0-beta.5","1.6.0-beta.2","1.6.0-beta.1","1.5.0-rc.1","1.5.0-beta.2","1.5.0-beta.1","1.3.0-rc.5","1.3.0-rc.4","1.3.0-rc.3","1.3.0-rc.1","1.2.0-rc.3","1.2.0-rc.2","1.2.0-rc.1","1.1.9-rc.3","1.1.9-rc.2","1.1.9-rc.1","1.1.0-rc.3","1.1.0-rc.2","1.1.0-rc.1","1.1.0-beta.5","1.1.0-beta.4","1.1.0-beta.3","1.1.0-beta.2","1.1.0-beta.1","0.9.19","0.9.18","0.9.17","0.9.16","0.9.15","0.9.14","0.9.13","0.9.12","0.9.11","0.9.10","0.9.9","0.9.8","0.9.7","0.9.6","0.9.5","0.9.4","0.9.3","0.9.2","0.9.0","0.8.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-34252.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}