CVE-2025-62874

Executive Summary

CVE-2025-62874 is a Missing Authorization vulnerability in the AnyComment WordPress plugin by Alexander, affecting versions up to and including 0.3.6. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions or data exposure. The vulnerability has a CVSS score of 4.3 (Medium), with an EPSS probability of 0.0%, indicating low active exploitation in the wild. As a WordPress plugin vulnerability, it directly impacts the WordPress ecosystem and does not involve Apache or Nginx server software.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users should verify the integrity of their plugin files and monitor for any unauthorized modifications. Since the patch status is unknown, the supply chain risk remains elevated until a fix is released.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The vulnerable component remains isolated.
• Confidentiality Impact: None (C:N) – No data disclosure.
• Integrity Impact: Low (I:L) – Limited modification of data or settings.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. The low EPSS score suggests limited active exploitation, but the lack of a patch increases risk for unpatched installations.

Deep Dive & Mechanics

The vulnerability resides in the AnyComment WordPress plugin, which provides commenting functionality. The issue is a Missing Authorization (CWE-862) flaw, meaning the plugin fails to properly verify that a user has the necessary permissions before performing certain actions. This allows an attacker to exploit incorrectly configured access control security levels, potentially enabling actions such as:

• Modifying comment settings without authentication.
• Accessing or altering comment data intended for administrators.
• Bypassing intended restrictions on comment moderation or display.

The vulnerability is triggered via HTTP requests to specific plugin endpoints that lack proper capability checks. Since the plugin is unpatched, any site running AnyComment <= 0.3.6 is vulnerable.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely lacks a current_user_can() or similar capability check before executing sensitive operations. A patched version would include proper authorization checks, such as:

if ( ! current_user_can( 'manage_options' ) ) {
    wp_die( 'Unauthorized' );
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with AnyComment plugin version <= 0.3.6.
• Network access to the site.

Exploitation Steps:

1. Identify the vulnerable endpoint (e.g., /wp-admin/admin-ajax.php?action=anycomment_*).
2. Craft a request without authentication to trigger the missing authorization.
3. Example using curl:

curl -X POST "http://target.com/wp-admin/admin-ajax.php" \
  -d "action=anycomment_update_settings&setting=moderation&value=disabled"

Note: No public exploit code is available; this is a conceptual example.

Blue Team (Detection & Defense)

Detection:

• Monitor for unauthorized access to AnyComment AJAX endpoints.
• Look for requests to admin-ajax.php with action=anycomment_* from unauthenticated users.

Defense:

• Disable or remove the AnyComment plugin until a patch is available.
• Implement Web Application Firewall (WAF) rules to block unauthenticated requests to plugin endpoints.
• Restrict access to /wp-admin/ directory via .htaccess or server configuration.

Indicators of Compromise (IOCs)

• File Paths:
  • /wp-content/plugins/anycomment/anycomment.php
  • /wp-content/plugins/anycomment/includes/class-anycomment-ajax.php
• Network Indicators:
  • HTTP POST requests to /wp-admin/admin-ajax.php with action=anycomment_* parameters.
  • Unusual patterns in WordPress debug logs (e.g., wp-content/debug.log).
• Log Entries:
  • [Date] [IP] POST /wp-admin/admin-ajax.php with no authentication cookie.

Detection Engineering

YARA Rule

rule Detect_AnyComment_Missing_Auth {
    meta:
        description = "Detects vulnerable AnyComment plugin files (<=0.3.6)"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-62874"
    strings:
        $vuln_func = "current_user_can" nocase
        $plugin_file = "anycomment.php" nocase
    condition:
        $plugin_file and not $vuln_func
}

Sigma Rule

title: AnyComment Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated requests to AnyComment AJAX endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=anycomment_'
        c-ip|notcontains: '127.0.0.1'
    condition: selection
falsepositives:
    - Legitimate admin actions (requires authentication)
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-62874 - AnyComment Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=anycomment_"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the AnyComment plugin until a patch is released.
2. Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to admin-ajax.php with action=anycomment_*.
3. Monitor logs for suspicious activity targeting the plugin.

Long-term Fix:

• Await an official patch from the vendor (Alexander). Once available, update to the patched version immediately.
• Consider replacing the plugin with an alternative that has active security support.

Workaround:

• Add the following to .htaccess to restrict access to the plugin directory:

<FilesMatch "anycomment">
    Require all denied
</FilesMatch>

Valters IT