CVE-2024-56940
📋 TL;DR
A vulnerability in LearnDash v6.7.1 allows attackers to cause Denial of Service (DoS) by uploading excessive files through the profile image upload function. This affects all LearnDash installations running the vulnerable version. The attack can disrupt service availability for legitimate users.
💻 Affected Systems
- LearnDash
📦 What is this software?
Learndash by Learndash
⚠️ Risk & Real-World Impact
Worst Case
Complete service unavailability for all users, requiring manual intervention to restore functionality and potentially causing extended downtime.
Likely Case
Temporary service degradation or unavailability during attack periods, impacting user experience and potentially causing data loss for in-progress activities.
If Mitigated
Minimal impact with proper rate limiting and file upload controls in place, potentially causing only minor performance degradation.
🎯 Exploit Status
Exploitation requires ability to upload files to the profile image function, which typically requires user authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: LearnDash v6.7.2 or later
Vendor Advisory: https://www.learndash.com/
Restart Required: No
Instructions:
1. Backup your WordPress site and database. 2. Update LearnDash plugin through WordPress admin panel. 3. Verify update to v6.7.2 or later. 4. Test profile image upload functionality.
🔧 Temporary Workarounds
Disable profile image uploads
allTemporarily disable the profile image upload functionality to prevent exploitation
Implement rate limiting
allAdd server-side rate limiting for file upload requests
🧯 If You Can't Patch
- Implement strict file upload limits (size, count, frequency) at web server level
- Monitor for abnormal upload patterns and block suspicious IP addresses
🔍 How to Verify
Check if Vulnerable:
Check LearnDash plugin version in WordPress admin panel under Plugins > Installed PluginsCheck Version:
wp plugin list --name=learndash --field=versionVerify Fix Applied:
Confirm LearnDash version is 6.7.2 or higher and test profile image upload with monitoring for resource exhaustion📡 Detection & Monitoring
Log Indicators:
- Unusually high frequency of file upload requests
- Multiple failed upload attempts from same user/IP
- Server resource exhaustion warnings
Network Indicators:
- Spike in POST requests to profile image upload endpoints
- Abnormal traffic patterns from single IP addresses
SIEM Query:
source="web_server" (method="POST" AND uri="*/wp-content/plugins/sfwd-lms/*upload*" OR uri="*/wp-admin/admin-ajax.php*action=upload*") | stats count by src_ip