CVE-2023-40035: Craftcms/cms Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-44wr-rmwq-3phw",
  "modified" : "2025-07-16T21:00:57Z",
  "published" : "2023-08-21T19:58:04Z",
  "aliases" : [ "CVE-2023-40035" ],
  "summary" : "Craft CMS vulnerable to Remote Code Execution via validatePath bypass",
  "details" : "### Summary\nBypassing the validatePath function can lead to potential Remote Code Execution\n(Post-authentication, ALLOW_ADMIN_CHANGES=true)\n\n### Details\n\nIn bootstrap.php, the SystemPaths path is set as below.\n```php\n// Set the vendor path. By default assume that it's 4 levels up from here\n$vendorPath = $findConfigPath('--vendorPath', 'CRAFT_VENDOR_PATH') ?? dirname(__DIR__, 3);\n\n// Set the \"project root\" path that contains config/, storage/, etc. By default assume that it's up a level from vendor/.\n$rootPath = $findConfigPath('--basePath', 'CRAFT_BASE_PATH') ?? dirname($vendorPath);\n\n// By default the remaining directories will be in the base directory\n$dotenvPath = $findConfigPath('--dotenvPath', 'CRAFT_DOTENV_PATH') ?? \"$rootPath/.env\";\n$configPath = $findConfigPath('--configPath', 'CRAFT_CONFIG_PATH') ?? \"$rootPath/config\";\n$contentMigrationsPath = $findConfigPath('--contentMigrationsPath', 'CRAFT_CONTENT_MIGRATIONS_PATH') ?? \"$rootPath/migrations\";\n$storagePath = $findConfigPath('--storagePath', 'CRAFT_STORAGE_PATH') ?? \"$rootPath/storage\";\n$templatesPath = $findConfigPath('--templatesPath', 'CRAFT_TEMPLATES_PATH') ?? \"$rootPath/templates\";\n$translationsPath = $findConfigPath('--translationsPath', 'CRAFT_TRANSLATIONS_PATH') ?? \"$rootPath/translations\";\n$testsPath = $findConfigPath('--testsPath', 'CRAFT_TESTS_PATH') ?? \"$rootPath/tests\";\n```\n\nBecause paths are validated based on the /path1/path2 format, this can be bypassed using a file URI scheme such as file:///path1/path2. File scheme is supported in mkdir()\n```php\n    /**\n     * @param string $attribute\n     * @param array|null $params\n     * @param InlineValidator $validator\n     * @return void\n     * @since 4.4.6\n     */\n    public function validatePath(string $attribute, ?array $params, InlineValidator $validator): void\n    {\n        // Make sure it’s not within any of the system directories\n        $path = FileHelper::absolutePath($this->getRootPath(), '/');\n\n        $systemDirs = Craft::$app->getPath()->getSystemPaths();\n\n        foreach ($systemDirs as $dir) {\n            $dir = FileHelper::absolutePath($dir, '/');\n            if (str_starts_with(\"$path/\", \"$dir/\")) {\n                $validator->addError($this, $attribute, Craft::t('app', 'Local volumes cannot be located within system directories.'));\n                break;\n            }\n        }\n    }\n```\n\nref. https://www.php.net/manual/en/wrappers.file.php\n\n\n\n### PoC\n1) Create a new filesystem. **Base Path: file:///var/www/html/templates**\n\n![1](https://user-images.githubusercontent.com/30969523/249252853-5cde9bae-9279-428a-972b-d4444c545819.png)\n\n\n2) Create a new asset volume. Asset Filesystem: local_bypass\n\n![2](https://user-images.githubusercontent.com/30969523/249256711-e37da7f8-52d6-4ecc-bfc4-b9b9d8a2230d.png)\n\n\n3) Upload a ttml file with rce template code. Confirm poc.ttml file created in /var/www/html/templates\n```twig\n{{'<pre>'}}\n{{1337*1337}}\n{{['cat /etc/passwd']|map('passthru')|join}}\n{{['id;pwd;ls -altr /']|map('passthru')|join}}\n```\n![3](https://user-images.githubusercontent.com/30969523/249256731-8dafc3dc-4937-4f69-bba0-97bc96be1ada.png)\n![4](https://user-images.githubusercontent.com/30969523/249257369-54e22aff-3919-4a21-b696-a7be74086ff9.png)\n\n\n4) Create a new route. URI: * , Template: poc.ttml\n\n![5](https://user-images.githubusercontent.com/30969523/249257437-972ec725-8197-4472-9b57-750ab91d9bfd.png)\n\n\n5) Confirm RCE on arbitrary path ( /* )\n\n![6](https://user-images.githubusercontent.com/30969523/249257465-061dbaf8-a2c6-4366-80f5-986a15bad748.png)\n\n\n#### PoC Env\n\n![0628 env](https://user-images.githubusercontent.com/30969523/249252784-6e5913ad-9ad1-4d3a-a70f-2c5ff9f55166.png)\n\n\n### Impact\nTake control of vulnerable systems, Data exfiltrations, Malware execution, Pivoting, etc.\n\nalthough the vulnerability is exploitable only in the authenticated users, configuration with ALLOW_ADMIN_CHANGES=true, there is still a potential security threat (Remote Code Execution)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0-RC1"
      }, {
        "fixed" : "4.4.15"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.4.14"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.8.15"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.8.14"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-44wr-rmwq-3phw"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-40035"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/0bd33861abdc60c93209cff03eeee54504d3d3b5"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/craftcms/cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/3.8.15"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/4.4.15"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-74" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-21T19:58:04Z",
    "nvd_published_at" : "2023-08-23T21:15:08Z"
  }
}