CVE-2025-26901

Executive Summary

CVE-2025-26901 is a Missing Authorization vulnerability in the Brizy Pro WordPress plugin, affecting versions up to and including 2.8.0. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions within the WordPress ecosystem. The vulnerability has a CVSS score of 4.3 (Medium), with an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or patch details are currently available.

Supply Chain & Package Security

This vulnerability affects the Brizy Pro plugin, distributed via the WordPress plugin repository and third-party marketplaces. As a WordPress plugin, it is part of the broader WordPress ecosystem and is not associated with Apache or Nginx. Users should verify the integrity of their plugin installations and monitor for updates from the vendor.

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)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: Low (I:L)
• Availability Impact: None (A:N)

The threat level is Medium, with low exploitation likelihood (EPSS 0.0%). However, the lack of authentication requirements makes it accessible to any remote attacker.

Deep Dive & Mechanics

The vulnerability resides in the Brizy Pro plugin's access control mechanisms. The plugin fails to properly validate user permissions when processing certain API requests or administrative actions. This allows an unauthenticated attacker to bypass authorization checks and perform actions that should require higher privileges, such as modifying plugin settings or accessing restricted data.

The root cause is a Missing Authorization check (CWE-862) in one or more functions that handle user input. The plugin does not verify whether the current user has the necessary capabilities before executing sensitive operations. This is a common issue in WordPress plugins where nonce checks or capability checks are omitted.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the Brizy Pro plugin files (e.g., brizy-pro.php or related modules). A typical vulnerable pattern might look like:

// Vulnerable code (missing capability check)
add_action('wp_ajax_brizy_pro_action', 'handle_brizy_pro_action');
function handle_brizy_pro_action() {
    // Process request without checking user capabilities
    update_option('brizy_pro_settings', $_POST['settings']);
}

A patched version would include a capability check:

// Patched code
add_action('wp_ajax_brizy_pro_action', 'handle_brizy_pro_action');
function handle_brizy_pro_action() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    update_option('brizy_pro_settings', $_POST['settings']);
}

Exploitation & Lab Setup

Red Team

To exploit this vulnerability in a lab environment:

1. Setup: Install WordPress with Brizy Pro version <= 2.8.0.
2. Reconnaissance: Identify the vulnerable endpoint (e.g., via wp-admin/admin-ajax.php with action brizy_pro_action).
3. Exploitation: Send a crafted HTTP request without authentication:

curl -X POST http://target/wp-admin/admin-ajax.php \
  -d "action=brizy_pro_action&settings[malicious]=value"

4. Verification: Check if the settings were modified without authentication.

Blue Team

To detect exploitation attempts:

1. Monitor Logs: Look for unauthorized access to admin-ajax.php with actions related to Brizy Pro.
2. Network Analysis: Detect unusual POST requests to /wp-admin/admin-ajax.php without valid nonce or authentication headers.
3. File Integrity: Monitor changes to WordPress options or plugin files.

Indicators of Compromise (IOCs)

• Network: POST requests to /wp-admin/admin-ajax.php with action=brizy_pro_* parameters from unauthenticated sources.
• File: Unauthorized modifications to wp_options table entries containing brizy_pro_settings.
• Log: Entries in WordPress debug log showing capability errors or unauthorized access attempts.

Detection Engineering

YARA Rule

rule CVE_2025_26901_Brizy_Pro_Missing_Auth {
    meta:
        description = "Detects Brizy Pro plugin files with missing authorization"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-26901"
    strings:
        $vuln_func = "add_action('wp_ajax_" nocase
        $missing_check = "current_user_can" nocase
    condition:
        $vuln_func and not $missing_check
}

Sigma Rule

title: CVE-2025-26901 Brizy Pro Missing Authorization
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects exploitation attempts against Brizy Pro missing authorization vulnerability
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=brizy_pro_'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-26901 Brizy Pro Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/wp-admin/admin-ajax.php";
    http_uri;
    content:"action=brizy_pro_";
    http_client_body;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the Brizy Pro plugin until a patch is available.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php with action=brizy_pro_* from unauthenticated sources.
3. Long-term: Apply vendor patch when released. Monitor the Brizy Pro changelog for version 2.8.1 or higher.
4. Compensating Controls: Restrict access to /wp-admin/ directory via .htaccess or IP whitelisting.

Valters IT
Securing Digital Frontiers