CVE-2024-11299

Executive Summary

CVE-2024-11299 is a Sensitive Information Exposure vulnerability in the Memberpress WordPress plugin (versions up to and including 1.11.37). The flaw resides in how the plugin interacts with the WordPress core search feature, allowing unauthenticated attackers to extract sensitive data from posts that are restricted to higher-level roles (e.g., administrator). This is a WordPress ecosystem issue, not related to the underlying web server (Apache/Nginx). The vulnerability has a CVSS score of 5.3 (Medium) and an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public exploit code or patch is currently available.

Supply Chain & Package Security

This vulnerability affects the Memberpress WordPress plugin, distributed via the WordPress plugin repository and commercial channels. As a WordPress plugin, it is part of a supply chain where site administrators must manually update. The lack of a patch increases risk for unmaintained sites.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 5.3 (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: Low (C:L) – limited exposure of restricted post data
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability allows information disclosure but not system compromise. The low EPSS score suggests limited active exploitation.

Deep Dive & Mechanics

The vulnerability exists because the Memberpress plugin fails to properly filter search results when the WordPress core search feature is used. When an unauthenticated user performs a search, the plugin’s access control checks are bypassed, exposing content from posts that should be restricted to administrators or other high-privilege roles.

Root Cause: The plugin does not integrate with WordPress’s pre_get_posts filter or similar hooks to exclude restricted posts from search results for unauthenticated users. This allows the default WordPress search to return sensitive data.

Attack Vector: An attacker sends a crafted search query to the WordPress site (e.g., /?s=confidential). The search results include excerpts or full content from restricted posts, leaking sensitive information.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable behavior:

Vulnerable Code (Conceptual):

// In Memberpress plugin, search filter is missing
add_action('pre_get_posts', 'memberpress_search_filter');
function memberpress_search_filter($query) {
    // No check for user role or post visibility
    // This allows all posts to appear in search results
}

Patched Code (Expected):

// Patched version would include role-based filtering
add_action('pre_get_posts', 'memberpress_search_filter');
function memberpress_search_filter($query) {
    if (!is_admin() && $query->is_search) {
        $query->set('post__not_in', get_restricted_post_ids());
    }
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Memberpress plugin <= 1.11.37
• At least one post restricted to administrator role

Exploitation Steps:

1. Identify the target WordPress site (e.g., https://target.com).
2. Perform a search query that matches content in a restricted post:

   https://target.com/?s=confidential
   

3. Examine the search results page. If the restricted post appears (even as an excerpt), the vulnerability is confirmed.
4. Use automated tools to enumerate search terms and extract data.

Proof-of-Concept (No public exploit available):

curl -s "https://target.com/?s=admin-only" | grep -oP 'class="entry-title">.*?</a>'

Blue Team (Detection & Response)

Detection:

• Monitor search query logs for unusual patterns (e.g., many searches for sensitive terms).
• Check for unauthenticated access to restricted post content via search results.

Response:

• Immediately restrict search functionality for unauthenticated users via a plugin or custom code.
• Apply the patch once available.
• Audit search logs for data exfiltration.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /?s= with terms matching restricted content.
• Logs: WordPress search logs showing unauthenticated queries for sensitive terms.
• File: No specific file IOCs; the vulnerability is logic-based.

Detection Engineering

YARA Rule

rule CVE_2024_11299_Memberpress_Search_Exposure {
    meta:
        description = "Detects Memberpress plugin versions vulnerable to CVE-2024-11299"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-11299"
    strings:
        $plugin_file = "memberpress.php"
        $version_pattern = /Version: 1\.11\.\d{1,2}/
    condition:
        $plugin_file and $version_pattern
}

Sigma Rule

title: CVE-2024-11299 Memberpress Search Data Exposure
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated search queries that may expose restricted Memberpress posts
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '?s='
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate search queries by authenticated users
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-11299 Memberpress Search Data Exposure"; flow:to_server; http.uri; content:"?s="; nocase; http.user_agent; content:"!"; distance:0; within:100; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable search for unauthenticated users using a plugin like "Disable Search" or custom code:

   add_action('init', 'disable_search_for_guests');
   function disable_search_for_guests() {
       if (!is_user_logged_in() && is_search()) {
           wp_redirect(home_url());
           exit;
       }
   }
   

2. Restrict access to sensitive posts by using a more robust access control plugin.
3. Monitor for updates from Memberpress and apply the patch as soon as it is released.

Long-term Fix:

• Upgrade Memberpress to a patched version (once available).
• Implement a Web Application Firewall (WAF) rule to block unauthenticated search queries.

Valters IT
DevSecOps & Cyber Threat Intelligence