CVE-2023-25365
📋 TL;DR
This vulnerability allows a local attacker to upload malicious .mp3 files containing XSS payloads to October CMS, which can then execute arbitrary JavaScript in victims' browsers when accessed. It affects October CMS version 3.2.0 installations where file upload functionality is enabled.
💻 Affected Systems
- October CMS
📦 What is this software?
October by Octobercms
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, deface websites, or redirect users to malicious sites, potentially leading to full account compromise.
Likely Case
Attackers with access to upload functionality can inject persistent XSS payloads that execute when other users view or interact with uploaded files.
If Mitigated
With proper file type validation and content security policies, the impact is limited to file upload functionality bypass attempts.
🎯 Exploit Status
Exploitation requires local access to upload files, but the XSS payload execution occurs when victims access the uploaded file.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.1 or later
Vendor Advisory: https://github.com/octobercms/october/security/advisories
Restart Required: No
Instructions:
1. Update October CMS to version 3.2.1 or later via composer update. 2. Clear application cache. 3. Verify file upload validation is working.
🔧 Temporary Workarounds
Disable .mp3 file uploads
allRestrict file uploads to exclude .mp3 extensions in October CMS configuration
Edit config/cms.php and modify allowedExtensions array to exclude 'mp3'
Implement Content Security Policy
allAdd CSP headers to prevent execution of inline scripts
Add header Content-Security-Policy: script-src 'self' to web server configuration
🧯 If You Can't Patch
- Implement strict file type validation at the web application firewall level
- Monitor and audit all file uploads for suspicious content patterns
🔍 How to Verify
Check if Vulnerable:
Check if running October CMS version 3.2.0 and test if .mp3 files with XSS payloads can be uploaded and executedCheck Version:
php artisan october:versionVerify Fix Applied:
Verify version is 3.2.1+ and test that .mp3 files with script tags are properly rejected or sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual .mp3 file uploads
- File upload attempts with script tags in filenames or content
- Multiple failed upload validation attempts
Network Indicators:
- HTTP POST requests to upload endpoints with .mp3 files
- Requests to uploaded .mp3 files followed by script execution patterns
SIEM Query:
source="web_logs" AND (uri_path="*upload*" AND file_extension="mp3") OR (uri_path="*.mp3" AND user_agent="*script*"))