CVE-2025-59547
📋 TL;DR
This vulnerability in DNN CMS allows attackers to upload files with Unicode characters that get translated into paths, potentially exposing internal network resources. It affects DNN versions before 10.1.0 where the CKEditor file upload endpoint is accessible. Attackers could probe internal network endpoints through the vulnerable file upload functionality.
💻 Affected Systems
- DNN (DotNetNuke)
📦 What is this software?
Dotnetnuke by Dnnsoftware
⚠️ Risk & Real-World Impact
Worst Case
Attackers could map internal network resources, discover sensitive systems, and potentially access internal-only services through path traversal.
Likely Case
Information disclosure about internal network structure and potentially accessing internal resources that shouldn't be exposed.
If Mitigated
Limited impact with proper network segmentation and file upload restrictions in place.
🎯 Exploit Status
Exploitation requires understanding of Unicode character translation and path traversal techniques
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.0
Vendor Advisory: https://github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-cgqj-mw4m-v7hp
Restart Required: No
Instructions:
1. Backup your DNN installation and database. 2. Download DNN Platform 10.1.0 or later. 3. Follow standard DNN upgrade procedures. 4. Verify the CKEditor component is updated.
🔧 Temporary Workarounds
Disable CKEditor file upload
allDisable or restrict access to the vulnerable CKEditor file upload endpoint
Modify web.config to restrict access to CKEditor upload handlers
Implement file upload validation
allAdd server-side validation to reject filenames containing Unicode characters that could translate to path traversal
Implement custom file upload validation in DNN modules
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the DNN server from internal resources
- Deploy a web application firewall (WAF) with rules to block Unicode-based path traversal attempts
🔍 How to Verify
Check if Vulnerable:
Check DNN version in Admin > Site Settings > Basic Settings, or examine the web.config file for version informationCheck Version:
Check the version in the DNN admin panel or examine the web.config fileVerify Fix Applied:
Verify DNN version is 10.1.0 or later and test file upload functionality with Unicode filenames📡 Detection & Monitoring
Log Indicators:
- Unusual file upload attempts with Unicode characters in filenames
- Multiple failed upload attempts with unusual paths
Network Indicators:
- Unusual outbound connections from DNN server to internal resources following upload attempts
SIEM Query:
source="dnn_logs" AND (filename CONTAINS "%" OR filename CONTAINS ".." OR filename MATCHES "[\u0000-\uFFFF]+")