CVE-2024-7817

Executive Summary

CVE-2024-7817 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the Misiek Photo Album WordPress plugin, affecting versions through 1.4.3. The plugin fails to implement CSRF tokens or nonces in certain administrative actions, allowing an attacker to trick a logged-in administrator into unknowingly deleting arbitrary photo albums. This is a classic WordPress ecosystem issue where plugin developers omit CSRF protection on sensitive endpoints.

The vulnerability has a CVSS score of 0.0 (pending official scoring) but is assessed as Medium severity due to the requirement for user interaction and the potential for data loss. No public exploit code or proof-of-concept is currently available, and the vendor has not released a patch. The EPSS score is 0.0%, indicating low exploitation likelihood at this time.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users who installed the plugin directly from the WordPress dashboard or via manual upload are affected. There is no known compromise of the plugin’s distribution channel, but the lack of a patch means the plugin should be considered abandoned and removed from all installations.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack is carried out over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – The attacker does not need to be authenticated.
• User Interaction (UI): Required (R) – The victim must be tricked into clicking a malicious link or visiting a crafted page.
• Scope (S): Unchanged (U) – The vulnerability does not affect other components.
• Confidentiality Impact (C): None (N) – No data exposure.
• Integrity Impact (I): Low (L) – Unauthorized deletion of albums.
• Availability Impact (A): None (N) – No denial of service.

Threat Level: Medium. The attack requires social engineering, but successful exploitation can result in permanent loss of photo album data.

Deep Dive & Mechanics

The Misiek Photo Album plugin provides a simple gallery management interface for WordPress. The vulnerability lies in the album deletion functionality, which is likely triggered via a GET or POST request to an endpoint such as /wp-admin/admin-ajax.php?action=delete_album&album_id=X. Because the plugin does not include a CSRF nonce (a unique, secret token) in the request, an attacker can craft a malicious HTML page that, when visited by an authenticated admin, automatically submits a request to delete a specific album.

The attack flow:

1. Attacker identifies a target WordPress site running the vulnerable plugin.
2. Attacker crafts a CSRF payload (e.g., an HTML form that auto-submits to the delete endpoint).
3. Attacker lures the admin to visit the malicious page (e.g., via email, forum post, or compromised site).
4. The admin’s browser sends the forged request with the admin’s session cookies.
5. The plugin processes the request without verifying the origin, deleting the album.

The vulnerability is specific to the WordPress ecosystem and does not involve server-level misconfigurations.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin’s main PHP file (e.g., misiek-photo-album.php). A typical vulnerable pattern:

// Vulnerable: No nonce check
add_action('wp_ajax_delete_album', 'delete_album_callback');
function delete_album_callback() {
    $album_id = $_GET['album_id'];
    // Delete album from database
    delete_album_from_db($album_id);
    wp_die();
}

A patched version would include a nonce verification:

// Patched: Nonce check added
add_action('wp_ajax_delete_album', 'delete_album_callback');
function delete_album_callback() {
    // Verify nonce
    if (!wp_verify_nonce($_GET['_wpnonce'], 'delete_album_nonce')) {
        wp_die('CSRF validation failed.');
    }
    $album_id = $_GET['album_id'];
    delete_album_from_db($album_id);
    wp_die();
}

The nonce is generated in the admin interface and passed with the request. Without it, the action is rejected.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with the Misiek Photo Album plugin (<=1.4.3) installed and activated.
• An authenticated admin session (the victim).
• A way to deliver the CSRF payload (e.g., email, social media).

Step-by-step exploitation:

1. Identify the delete endpoint: Use browser developer tools or inspect the plugin’s source to find the exact URL and parameters for album deletion. Example: http://target/wp-admin/admin-ajax.php?action=delete_album&album_id=5.

2. Craft the CSRF payload: Create an HTML file that auto-submits a form to the delete endpoint.

<html>
<body>
<form id="csrf" action="http://target/wp-admin/admin-ajax.php" method="GET">
  <input type="hidden" name="action" value="delete_album">
  <input type="hidden" name="album_id" value="5">
</form>
<script>document.getElementById('csrf').submit();</script>
</body>
</html>

3. Host the payload: Place the HTML file on a server you control (e.g., http://attacker.com/exploit.html).

4. Deliver the payload: Send the link to the admin via email or social engineering.

5. Trigger the attack: When the admin visits the link, the album with ID 5 is deleted.

Note: No public exploit code exists; this is a theoretical demonstration.

Blue Team (Defense & Detection)

Detection:

• Monitor for unusual admin-ajax.php requests with action=delete_album from unexpected referrers.
• Look for a high volume of album deletion requests in a short time.
• Check server logs for GET /wp-admin/admin-ajax.php?action=delete_album with no _wpnonce parameter.

Prevention:

• Disable or remove the Misiek Photo Album plugin immediately.
• Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php that lack a valid nonce.
• Educate administrators about phishing attacks that could trigger CSRF.

Indicators of Compromise (IOCs)

• Network:
  • HTTP requests to /wp-admin/admin-ajax.php with action=delete_album and no _wpnonce parameter.
  • Referrer headers from external domains (e.g., http://attacker.com).
• File System:
  • Presence of the plugin directory: /wp-content/plugins/misiek-photo-album/.
• Logs:
  • WordPress debug log entries showing album deletion without nonce.
  • Web server access logs with admin-ajax.php requests from unusual IPs.

Detection Engineering

YARA Rule

rule CVE_2024_7817_Misiek_Photo_Album_CSRF {
    meta:
        description = "Detects vulnerable Misiek Photo Album plugin files lacking CSRF nonce"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-7817"
    strings:
        $vuln_func = "add_action('wp_ajax_delete_album'" nocase
        $no_nonce = "wp_verify_nonce" nocase
    condition:
        $vuln_func and not $no_nonce
}

Sigma Rule

title: CVE-2024-7817 - Misiek Photo Album CSRF Exploitation Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests targeting the vulnerable delete_album action without a nonce parameter.
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-7817
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'GET'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=delete_album'
        cs-uri-query|not_contains: '_wpnonce'
    condition: selection
falsepositives:
    - Legitimate admin actions if nonce is passed via other means (unlikely)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2024-7817 - Misiek Photo Album CSRF Delete Album Attempt";
    flow:to_server,established;
    http.method;
    content:"GET";
    http.uri;
    content:"/wp-admin/admin-ajax.php";
    http.uri;
    content:"action=delete_album";
    http.uri;
    content:!"_wpnonce";
    classtype:attempted-user;
    sid:1000001;
    rev:1;
    reference:cve,2024-7817;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin: Deactivate and delete the Misiek Photo Album plugin from all WordPress installations.
2. Audit for data loss: Check if any albums have been deleted without authorization. Restore from backups if necessary.
3. Update WordPress core and other plugins: Ensure all components are up-to-date to reduce attack surface.

Long-term Recommendations:

• Replace the plugin: Use an alternative, actively maintained photo album plugin that follows WordPress security best practices (e.g., NextGEN Gallery, Envira Gallery).
• Implement CSRF protection: For any custom development, always use WordPress nonces (wp_nonce_field(), check_admin_referer()) on all forms and AJAX actions.
• Monitor for similar vulnerabilities: Subscribe to WordPress security advisories and use a vulnerability scanner.

Patch Status: No official patch is available. The vendor (Misiek) has not responded. The only mitigation is to remove the plugin.

Valters IT