GHSA-jq29-c7v8-rg55
Suggest an improvement- Source
- https://github.com/advisories/GHSA-jq29-c7v8-rg55
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-jq29-c7v8-rg55/GHSA-jq29-c7v8-rg55.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-jq29-c7v8-rg55
- Aliases
- Published
- 2026-09-17T20:34:05Z
- Modified
- 2026-09-17T20:45:05Z
- Severity
-
- 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H CVSS Calculator
- 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Grav: Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion
- Details
-
Path Traversal in MediaUploadTrait::deleteFile() Allows Arbitrary File Deletion
Summary
A path traversal vulnerability in
MediaUploadTrait::deleteFile()allows an authenticated user with media management permissions to delete arbitrary files on the server. The method validates only the basename portion of the filename usingUtils::checkFilename(), while the directory path (which may contain../sequences) is preserved and passed unvalidated tounlink(). This enables directory escape from the intended media storage path.Severity
High (8.1) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CWE
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Details
In
system/src/Grav/Common/Media/Traits/MediaUploadTrait.php, thedeleteFile()method (lines 332-365) performs filename validation only on the basename, not the full path:public function deleteFile(string $filename, ?array $settings = null): void { $settings = $this->getUploadSettings($settings); $filesystem = Filesystem::getInstance(false); // Line 339-340: Only the BASENAME is validated $basename = $filesystem->basename($filename); // e.g. "evil.jpg" from "../../evil.jpg" if (!Utils::checkFilename($basename)) { // passes - no traversal in basename throw new RuntimeException(/* ... */); } $path = $settings['destination'] ?? $this->getPath(); // ... // Line 353: Full pathname (with traversal) is preserved $pathname = $filesystem->pathname($filename); // "../../" // Line 356-357: Traversal path reconstructed [$base, $ext,,] = $this->getFileParts($basename); $name = "{$pathname}{$base}.{$ext}"; // "../../evil.jpg" // Line 360: Passed to doRemove() $this->doRemove($name, $path); }doRemove()(line 521-582) then calls:// Line 538 unlink("{$folder}/{$filename}"); // e.g. unlink("/var/www/grav/user/pages/mypage/../../config/system.yaml")Utils::checkFilename()(lines 1022-1044) properly checks for/,\, and.., but it is applied to$filesystem->basename($filename)(the last path component only), so traversal sequences in the directory portion are never validated.Data flow from user input
The vulnerability is reachable through the Flex media handling pipeline:
FlexMediaTrait::setUpdatedMedia()(line 386) iterates form flash data where$filenameis the array key - user-controlled- For file deletions (
$fileis null, line 396), NO upload validation is performed (thecheckUploadedFile()call at line 401 only executes when$fileis truthy) - The raw filename is stored in
$this->_uploadsat line 414 saveUpdatedMedia()(line 499) calls$media->deleteFile($filename, $settings)with the unsanitized filename
Sibling: renameFile()
The same pattern exists in
renameFile()(lines 374-405) which has even weaker validation - it performs NOcheckFilename()call at all. WhilerenameFile()currently has no callers in the core codebase, it is part of the publicMediaUploadInterfaceand should be fixed as defense-in-depth.Proof of Concept
Environment: Grav CMS 2.0.16 with admin plugin
The attack requires an authenticated admin user with page/media editing permissions (not super-admin).
- Create a target file:
echo "DELETE_ME" > /var/www/grav/user/data/target.txt- Submit a Flex object form (e.g. page edit) with a crafted media deletion where the filename key contains path traversal:
POST /admin/pages/mypage/task:save Content-Type: multipart/form-data # The form flash data includes a media deletion entry with key: # "../../data/target.txt" -> null (deletion marker)-
When
saveUpdatedMedia()processes the deletion queue:$filename=../../data/target.txtdeleteFile("../../data/target.txt")is called$basename=target.txt(passescheckFilename())$pathname=../../data/$name=../../data/target.txtdoRemove()callsunlink("/var/www/grav/user/pages/mypage/../../data/target.txt")- Which resolves to
unlink("/var/www/grav/user/data/target.txt")
-
The file is deleted outside the intended media directory.
Impact
An authenticated user with media management permissions can:
- Delete configuration files (
user/config/system.yaml,user/config/security.yaml) - Delete other pages' content files
- Delete authentication-related files (user account YAML files)
- Cause denial of service by removing critical application files
- Potentially escalate privileges by removing security configuration
Suggested Fix
Apply
Utils::checkFilename()to the full$filenameparameter before decomposing it, or reject any filename containing directory separators or..sequences:public function deleteFile(string $filename, ?array $settings = null): void { $settings = $this->getUploadSettings($settings); $filesystem = Filesystem::getInstance(false); // Validate the FULL filename, not just the basename if (!Utils::checkFilename($filename)) { throw new RuntimeException(/* ... */); } // ... rest unchanged }The same fix should be applied to
renameFile()for both$fromand$toparameters.References
- Vulnerable file:
system/src/Grav/Common/Media/Traits/MediaUploadTrait.phplines 332-365, 521-582 - Caller:
system/src/Grav/Framework/Flex/Traits/FlexMediaTrait.phplines 386-414, 490-499 - Sibling:
system/src/Grav/Common/Media/Traits/MediaUploadTrait.phplines 374-405 (renameFile) - Related GHSA: GHSA-g6j3-8jv9-ch5f (path traversal in PagesController::batchCopy - different file, same bug class)
Disclosure
This vulnerability was discovered using AI-assisted security research tools.
- Database specific
{ "cwe_ids": [ "CWE-22" ], "github_reviewed": true, "github_reviewed_at": "2026-09-17T20:34:05Z", "nvd_published_at": null, "severity": "HIGH" }- References
Affected packages
Packagist / getgrav/grav
Package
- Name
- getgrav/grav
- Purl
- pkg:composer/getgrav/grav
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed2.0.16