CVE-2025-49991

Executive Summary

CVE-2025-49991 is a Missing Authorization vulnerability in the WordPress plugin WP-Recall, affecting versions from n/a through 16.26.14. This flaw allows an unauthenticated attacker to access functionality that should be constrained by Access Control Lists (ACLs). The vulnerability is classified under CWE-862 (Missing Authorization) and carries a CVSS score of 5.3 (Medium). No public proof-of-concept (PoC) or exploit code has been identified at this time, and the patch status remains unknown. The attack vector is network-based, requires no authentication, and has low complexity, making it a potential risk for unpatched WordPress sites.

Supply Chain & Package Security

This vulnerability affects the WordPress plugin ecosystem. WP-Recall is a community and social networking plugin for WordPress. The missing authorization flaw could allow attackers to access private user data, modify settings, or perform actions reserved for higher-privileged users. Since the patch status is unknown, site administrators should consider disabling the plugin until a fix is released.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality Impact (C): Low (L) – Limited information disclosure.
• Integrity Impact (I): None (N) – No data modification.
• Availability Impact (A): None (N) – No denial of service.

CVSS Score: 5.3 (Medium)
Threat Level: Medium – The vulnerability is easy to exploit but has limited impact on confidentiality.

Deep Dive & Mechanics

The WP-Recall plugin provides social networking features for WordPress, including user profiles, messaging, and activity feeds. The missing authorization vulnerability likely exists in one or more AJAX handlers or REST API endpoints that fail to properly verify user capabilities before executing sensitive operations.

Root Cause: The plugin does not enforce capability checks (e.g., current_user_can()) on certain functions accessible via HTTP requests. This allows any unauthenticated user to invoke these functions.

Attack Vector: An attacker can send crafted HTTP requests to the vulnerable endpoint(s) without authentication. For example, a request to wp-admin/admin-ajax.php with a specific action parameter could trigger a function that retrieves private user data or modifies plugin settings.

Impact: Successful exploitation could lead to:

• Unauthorized access to private user information (e.g., email addresses, profile data).
• Modification of plugin settings (e.g., disabling security features).
• Potential privilege escalation if the vulnerable function allows creating or modifying user accounts.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable code pattern. The fix would involve adding proper capability checks.

Vulnerable Code (Hypothetical):

add_action('wp_ajax_nopriv_my_action', 'my_function');
function my_function() {
    // No capability check
    $user_data = get_userdata($_POST['user_id']);
    echo json_encode($user_data);
    wp_die();
}

Patched Code (Hypothetical):

add_action('wp_ajax_nopriv_my_action', 'my_function');
function my_function() {
    if (!current_user_can('read')) {
        wp_die('Unauthorized', 403);
    }
    $user_data = get_userdata($_POST['user_id']);
    echo json_encode($user_data);
    wp_die();
}

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress (latest version) on a local server (e.g., XAMPP, Docker).
2. Install WP-Recall plugin version 16.26.14.
3. Create a test user with subscriber role.

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing plugin source code or using fuzzing tools.
2. Send a crafted HTTP request to the vulnerable endpoint without authentication.
3. Example using curl:

   curl -X POST http://target/wp-admin/admin-ajax.php \
   -d "action=vulnerable_action&user_id=1"
   

4. Observe the response containing sensitive data.

Note: No public exploit code is available. The above is a generic example.

Blue Team (Defensive)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with unknown action parameters.
• Look for requests from unauthenticated users to endpoints that should require authentication.
• Use Web Application Firewall (WAF) rules to block requests to known vulnerable endpoints.

Mitigation:

• Disable the WP-Recall plugin until a patch is released.
• Implement virtual patching via WAF rules.
• Restrict access to wp-admin/admin-ajax.php using .htaccess or server configuration.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /wp-admin/admin-ajax.php with action parameters not associated with legitimate plugin functionality.
  • Requests from IP addresses not associated with authenticated users.
• File IOCs:
  • Modified plugin files (e.g., wp-content/plugins/wp-recall/).
  • Unexpected files in the WordPress uploads directory.
• Log IOCs:
  • WordPress debug log entries showing unauthorized access attempts.
  • Web server access logs with 200 responses to admin-ajax.php from unauthenticated users.

Detection Engineering

YARA Rule

rule CVE_2025_49991_WP_Recall_Missing_Auth {
    meta:
        description = "Detects WP-Recall plugin files vulnerable to CVE-2025-49991"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49991"
    strings:
        $vuln_func = "wp_ajax_nopriv_" nocase
        $no_cap = "current_user_can" nocase
    condition:
        $vuln_func and not $no_cap
}

Sigma Rule

title: CVE-2025-49991 - WP-Recall Missing Authorization
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated access to WP-Recall AJAX endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri: '/wp-admin/admin-ajax.php'
        cs-uri-query: 'action=*'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate plugin AJAX calls
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-49991 - WP-Recall Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action="; http_client_body;
    classtype:attempted-recon;
    sid:10000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the WP-Recall plugin until a security patch is released.
2. Monitor logs for unauthorized access attempts.
3. Implement WAF rules to block requests to admin-ajax.php with unknown action parameters.

Long-term Fix:

• The vendor must release a patched version that includes proper capability checks (e.g., current_user_can()) on all AJAX handlers.
• Users should update to the latest version once available.

Workarounds:

• Use .htaccess to restrict access to admin-ajax.php:

  <Files "admin-ajax.php">
      Require all denied
  </Files>
  

  (Note: This may break legitimate AJAX functionality.)

Valters IT
Securing Digital Frontiers