{"id":"CVE-2023-34252","state":"PUBLISHED","title":"Grav Server-side Template Injection via Insufficient Validation in filterFilter","description":"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.","publishedAt":"2023-06-14T21:38:48.358Z","updatedAt":"2024-12-18T19:03:09.288Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["getgrav grav"],"affected":[{"vendor":"getgrav","product":"grav","versions":[{"version":"< 1.7.42","status":"affected"}]}],"references":["https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w","https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec","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"],"weaknesses":["CWE-184","CWE-1336"],"ingestedAt":"2026-10-29T20:06:00.499Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/34xxx/CVE-2023-34252.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2023-34252","state":"PUBLISHED","datePublished":"2023-06-14T21:38:48.358Z","dateUpdated":"2024-12-18T19:03:09.288Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2023-05-31T13:51:51.174Z"},"containers":{"cna":{"title":"Grav Server-side Template Injection via Insufficient Validation in filterFilter","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"getgrav","product":"grav","versions":[{"version":"< 1.7.42","status":"affected"}]}],"references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w","name":"https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec","name":"https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec","tags":["x_refsource_MISC"]},{"url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698","name":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698","tags":["x_refsource_MISC"]},{"url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074","name":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-184","lang":"en","description":"CWE-184: Incomplete List of Disallowed Inputs","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-1336","lang":"en","description":"CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2023-06-14T22:17:06.852Z"},"source":{"advisory":"GHSA-96xv-rmwj-6p9w","discovery":"UNKNOWN"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w","name":"https://github.com/getgrav/grav/security/advisories/GHSA-96xv-rmwj-6p9w","tags":["x_refsource_CONFIRM","x_transferred"]},{"url":"https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec","name":"https://github.com/getgrav/grav/commit/244758d4383034fe4cd292d41e477177870b65ec","tags":["x_refsource_MISC","x_transferred"]},{"url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698","name":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Twig/Extension/GravExtension.php#L1692-L1698","tags":["x_refsource_MISC","x_transferred"]},{"url":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074","name":"https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L1956-L2074","tags":["x_refsource_MISC","x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-02T16:01:54.351Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-12-18T19:02:44.830549Z","id":"CVE-2023-34252","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-12-18T19:03:09.288Z"}}]}}}