CVE-2024-13588
📋 TL;DR
The Simplebooklet PDF Viewer WordPress plugin has a stored XSS vulnerability that allows authenticated attackers with contributor-level access or higher to inject malicious scripts into website pages. These scripts execute whenever users view the compromised pages, potentially stealing credentials or performing unauthorized actions. All WordPress sites using Simplebooklet plugin versions 1.1.0 and earlier are affected.
💻 Affected Systems
- Simplebooklet PDF Viewer and Embedder WordPress Plugin
📦 What is this software?
Simplebooklet by Simplebooklet
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, take over the WordPress site, install backdoors, deface the website, or redirect visitors to malicious sites.
Likely Case
Attackers with contributor access inject malicious scripts to steal user session cookies, perform actions as other users, or display phishing content to visitors.
If Mitigated
With proper user role management and input validation, the risk is limited to trusted contributors who could still cause damage but would be traceable.
🎯 Exploit Status
Exploitation requires authenticated access (contributor role or higher). The vulnerability is in the 'simplebooklet' shortcode attribute handling.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1.1 or later
Vendor Advisory: https://wordpress.org/plugins/simplebooklet/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Go to Plugins → Installed Plugins. 3. Find Simplebooklet PDF Viewer. 4. Click 'Update Now' if update available. 5. If no update appears, manually download version 1.1.1+ from WordPress.org and replace plugin files.
🔧 Temporary Workarounds
Disable Simplebooklet Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate simplebooklet
Restrict User Roles
allRemove contributor access from untrusted users
wp user list --role=contributor
wp user set-role <username> subscriber
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads in shortcode attributes
- Audit all posts/pages for suspicious 'simplebooklet' shortcode usage and remove unauthorized content
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Simplebooklet PDF Viewer version. If version is 1.1.0 or earlier, you are vulnerable.Check Version:
wp plugin get simplebooklet --field=versionVerify Fix Applied:
After updating, verify plugin version shows 1.1.1 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual post/page edits by contributor users
- Multiple failed login attempts followed by successful contributor login
- Posts containing suspicious 'simplebooklet' shortcode attributes
Network Indicators:
- Outbound connections to suspicious domains from your WordPress site
- Unexpected JavaScript loading from your domain
SIEM Query:
source="wordpress" AND (event="post_modified" OR event="plugin_updated") AND plugin="simplebooklet"