CVE-2025-62867

Executive Summary

CVE-2025-62867 is a Missing Authorization vulnerability in the Ergonet Cache WordPress plugin (ergonet-varnish-cache), affecting versions from n/a through 1.0.13. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized access to cached data or administrative functions. 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 or patch is currently available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the WordPress plugin repository. Users should verify the integrity of their plugin installation and monitor for updates from the vendor. Since no patch is available, consider disabling the plugin until a fix is released.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The vulnerability allows an attacker to bypass authorization checks, potentially exposing sensitive cached data. The low EPSS score suggests limited active exploitation, but the lack of a patch increases long-term risk.

Deep Dive & Mechanics

The Ergonet Cache plugin (ergonet-varnish-cache) is designed to integrate with Varnish Cache for WordPress. The missing authorization vulnerability exists in the plugin's administrative or data-access endpoints, where access control checks are improperly implemented or missing entirely. An attacker can send crafted HTTP requests to these endpoints without authentication, potentially retrieving cached content or modifying cache settings.

The root cause is a failure to validate user permissions before executing sensitive operations, likely due to missing current_user_can() checks in WordPress plugin hooks or AJAX handlers.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is speculative but typical for such plugins:

Vulnerable Code (hypothetical):

add_action('wp_ajax_nopriv_ergonet_cache_flush', 'ergonet_cache_flush_handler');
function ergonet_cache_flush_handler() {
    // Missing permission check
    varnish_flush_all();
    wp_die();
}

Patched Code (expected):

add_action('wp_ajax_ergonet_cache_flush', 'ergonet_cache_flush_handler');
function ergonet_cache_flush_handler() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    varnish_flush_all();
    wp_die();
}

The patch would add capability checks and restrict AJAX actions to authenticated users with appropriate roles.

Exploitation & Lab Setup

Red Team

1. Reconnaissance: Identify WordPress sites using the Ergonet Cache plugin via Shodan dorks or web crawling.
2. Exploitation: Send unauthenticated requests to vulnerable endpoints, e.g.:

   curl -X POST http://target/wp-admin/admin-ajax.php?action=ergonet_cache_flush
   

   Or access cached data directly:

   curl http://target/?ergonet_cache_dump=1
   

3. Post-Exploitation: Extract cached content containing sensitive data (e.g., session tokens, API keys) or disrupt caching operations.

Blue Team

1. Detection: Monitor for unusual AJAX requests to admin-ajax.php with actions related to Ergonet Cache from unauthenticated sources.
2. Honeypot: Deploy a fake endpoint mimicking the vulnerable action to capture attacker behavior.
3. Mitigation: Implement a Web Application Firewall (WAF) rule to block requests to known vulnerable endpoints unless authenticated.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /wp-admin/admin-ajax.php with action parameters like ergonet_cache_flush, ergonet_cache_dump, or similar.
• File: Presence of the plugin directory /wp-content/plugins/ergonet-varnish-cache/ with version <= 1.0.13.
• Log: WordPress debug logs showing unauthenticated access to plugin-specific AJAX handlers.

Detection Engineering

YARA Rule

rule detect_ergonet_cache_vuln {
    meta:
        description = "Detects Ergonet Cache plugin files with missing authorization"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-62867"
    strings:
        $vuln_func = "wp_ajax_nopriv_" nocase
        $plugin_name = "ergonet-varnish-cache" nocase
    condition:
        $plugin_name and $vuln_func
}

Sigma Rule

title: Unauthenticated Access to Ergonet Cache AJAX Endpoints
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated requests to Ergonet Cache plugin AJAX actions
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=ergonet_cache'
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-62867 Ergonet Cache Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=ergonet_cache"; http_uri;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

• Immediate: Disable the Ergonet Cache plugin until a patch is released.
• Short-term: Implement a WAF rule to block unauthenticated requests to plugin-specific AJAX endpoints.
• Long-term: Monitor the vendor's website for updates and apply the patch as soon as it becomes available. Consider migrating to an alternative caching solution with active security support.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert