Packagist · nukeviet/nukeviet
NukeViet: Path Traversal to Arbitrary File Deletion in Edit Comment Function
Path Traversal to Arbitrary File Deletion in the Edit Comment admin function. An authenticated administrator can delete arbitrary files within the application root (e.g., config.php) by injecting a crafted attach parameter, rendering the application inoperable.
modules/comment/admin/edit.php
In the vulnerable version, the attach parameter received via HTTP POST was not validated before being processed:
// Vulnerable code (before fix)
$attach = $nv_Request->get_string('attach', 'post', '', true);
if (!empty($attach)) {
$attach = substr($attach, strlen(NV_BASE_SITEURL . NV_UPLOADS_DIR . '/' . $module_upload . '/'));
}
substr() strips the first N characters (equal to the length of the upload URL prefix, e.g. 26 chars for /nukeviet/uploads/comment/). By padding the payload with exactly 26 arbitrary characters followed by a path traversal sequence, an attacker can store ../../<target> directly into the database.
When the comment is subsequently deleted, del.php reads attach from the database and calls:
nv_deletefile(NV_UPLOADS_REAL_DIR . '/' . $module_upload . '/' . $row['attach']);
nv_deletefile() resolves the path via realpath() and only verifies the result is within NV_ROOTDIR — it does not restrict deletion to the uploads directory — allowing deletion of any file in the installation root.
attach parameter to:aaaaaaaaaaaaaaaaaaaaaaaaaa../../config.php
(26 padding characters + traversal path)
../../config.php is now stored in the database.config.php is deleted from the application root.NV_ROOTDIR can be permanently deleted.config.php causes a full application outage and exposes the install wizard.CVSS v3.1 Base Score: 8.7 (High)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H
| Metric | Value |
|---|---|
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | High (Admin required) |
| User Interaction | None |
| Scope | Changed |
| Confidentiality | None |
| Integrity | High |
| Availability | High |
Added nv_is_file() validation before processing the attach value. This function uses realpath() and a regex check to ensure the file resolves to a path within the intended upload directory, rejecting any traversal attempts.
// Fixed code
$attach = $nv_Request->get_string('attach', 'post', '');
if (!empty($attach) and nv_is_file($attach, NV_UPLOADS_DIR . '/' . $module_upload)) {
$attach = substr($attach, strlen(NV_BASE_SITEURL . NV_UPLOADS_DIR . '/' . $module_upload . '/'));
} else {
$attach = '';
}
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Check my repoSources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.