CVE-2023-1338
📋 TL;DR
The RapidLoad Power-Up for Autoptimize WordPress plugin versions up to 1.7.1 contain a missing capability check vulnerability in the attach_rule function. This allows authenticated attackers with subscriber-level permissions to modify cache rules, potentially disrupting website performance or causing denial of service. WordPress sites using vulnerable plugin versions are affected.
💻 Affected Systems
- RapidLoad Power-Up for Autoptimize WordPress plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could modify cache rules to cause website performance degradation, inject malicious content into cached pages, or create denial of service conditions affecting site availability.
Likely Case
Malicious users with subscriber accounts could disrupt website caching, causing performance issues or inconsistent content delivery to legitimate users.
If Mitigated
With proper access controls and monitoring, impact is limited to minor cache manipulation that can be quickly detected and reverted.
🎯 Exploit Status
Exploitation requires authenticated access with subscriber privileges. The vulnerability is straightforward to exploit once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.7.2 or later
Vendor Advisory: https://plugins.trac.wordpress.org/changeset/2877726/unusedcss/trunk/includes/modules/unused-css/UnusedCSS_Admin.php
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'RapidLoad Power-Up for Autoptimize'. 4. Click 'Update Now' if available, or manually update to version 1.7.2+. 5. Verify plugin is active and functioning.
🔧 Temporary Workarounds
Temporarily disable plugin
allDisable the vulnerable plugin until patched version can be installed
wp plugin deactivate rapidload-power-up-for-autoptimize
Restrict subscriber capabilities
allTemporarily remove or restrict subscriber user role capabilities
Use WordPress role editor plugins or custom code to modify subscriber capabilities
🧯 If You Can't Patch
- Monitor user activity logs for unauthorized cache modification attempts
- Implement web application firewall rules to detect and block suspicious cache-related requests
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel > Plugins > Installed Plugins, find RapidLoad Power-Up for Autoptimize and verify version is 1.7.1 or lowerCheck Version:
wp plugin get rapidload-power-up-for-autoptimize --field=versionVerify Fix Applied:
After updating, verify plugin version shows 1.7.2 or higher in WordPress plugins list📡 Detection & Monitoring
Log Indicators:
- Unusual cache rule modifications from subscriber-level users
- Multiple failed or successful cache modification attempts from non-admin users
Network Indicators:
- HTTP POST requests to cache-related endpoints from unauthorized user roles
SIEM Query:
source="wordpress.log" AND ("attach_rule" OR "cache modification") AND user_role="subscriber"🔗 References
- https://plugins.trac.wordpress.org/changeset/2877726/unusedcss/trunk/includes/modules/unused-css/UnusedCSS_Admin.php?contextall=1&old=2847136&old_path=%2Funusedcss%2Ftrunk%2Fincludes%2Fmodules%2Funused-css%2FUnusedCSS_Admin.php
- https://www.wordfence.com/threat-intel/vulnerabilities/id/1bb55b22-a0d0-424f-8e4f-57d3f239c149
- https://plugins.trac.wordpress.org/changeset/2877726/unusedcss/trunk/includes/modules/unused-css/UnusedCSS_Admin.php?contextall=1&old=2847136&old_path=%2Funusedcss%2Ftrunk%2Fincludes%2Fmodules%2Funused-css%2FUnusedCSS_Admin.php
- https://www.wordfence.com/threat-intel/vulnerabilities/id/1bb55b22-a0d0-424f-8e4f-57d3f239c149
