Published by CyberDudeBivash • Date: Nov 1, 2025 (IST)

DNN 10.0 Flaw Defense Toolkit: Custom WAF Rules and Patching Scripts for CVE-2025-64095

CVE-2025-64095 (CVSS ~10) impacts DNN prior to 10.1.1: the default HTML editor provider allows unauthenticated file uploads and can overwrite existing files, enabling defacement and XSS chaining. Patch to 10.1.1+ and apply the WAF & hardening rules below to shield your sites immediately. CyberDudeBivash Ecosystem:Apps & Services · CyberBivash (Threat Intel) · CryptoBivash · News Portal · Subscribe: ThreatWire

TL;DR — Act in This Order

Block upload vectors at edge: deploy the WAF rules below (ModSecurity/CRS, nginx, IIS URL Rewrite, Azure WAF). Target DNN editor endpoints, suspicious extensions, and overwrite attempts.
Hunt indicators: scan IIS logs for anonymous POST to editor/upload paths, mismatched Content-Type, and sudden 200 on image paths followed by defacement.
Patch now: upgrade to DNN 10.1.1 or later (vendor advisory). This version fixes the unauthenticated upload/overwrite issue.

1) About CVE-2025-64095 & Affected Versions

The DNN (DotNetNuke) platform’s default HTML editor provider permits unauthenticated uploads and can overwrite existing files prior to 10.1.1, enabling defacement and XSS chaining. The project’s advisory and CVE describe this as a critical issue, fixed in 10.1.1.

Related 2025 DNN issues (context): login IP filter bypass (pre-10.0.1), editor OOB upload exposure (CVE-2025-62802), Prompt module XSS (pre-10.1.0). Ensure a cumulative update strategy.

2) Edge Defenses — Ready-to-Use WAF Rules

Notes: treat these as deny-by-default guardrails while you patch. Tune for your upload workflows. No exploit payloads here.

ModSecurity (OWASP CRS)

# Block unauthenticated uploads to known editor/upload endpoints
SecAction "id:6409501,phase:1,pass,nolog,ctl:ruleEngine=On"

SecRule REQUEST_METHOD "@streq POST" "id:6409502,phase:2,deny,status:403,t:none,\
 msg:'DNN Upload Path Block (CVE-2025-64095)',\
 chain"
  SecRule REQUEST_URI "@pmFromFile dnn_upload_paths.txt"

# Deny dangerous extensions even if disguised
SecRule FILES_NAMES "\.(aspx?|ashx|config|cshtml|vbhtml|exe|dll|ps1|jsp|php|pl)$" \
 "id:6409503,phase:2,deny,status:403,msg:'Dangerous extension upload blocked'"

# Prevent overwrite attempts via same filename in media directories
SecRule REQUEST_URI "(?i)/Portals/.+\.(jpg|png|gif|svg)$" \
 "id:6409504,phase:2,deny,chain,msg:'Overwrite attempt to media path'"
  SecRule &FILES "!@eq 0"

nginx (reverse proxy)

# Block editor upload endpoints and restrict verbs
location ~* /(DesktopModules|Providers)/.*(Upload|FileManager|ImageHandler|CKEditor)/ {
    limit_except GET { deny all; }  # tighten if editor must accept POST, then allowlist auth path only
    return 403;
}

# Global deny for dangerous extensions on upload paths
location ~* /(Portals|Images|Providers)/.*\.(aspx?|ashx|config|dll|exe|ps1)$ { return 403; }

Azure Application Gateway WAF (OWASP CRS)

{
  "ruleSetType": "OWASP",
  "ruleSetVersion": "3.2",
  "exclusions": [],
  "customRules": [{
    "name": "DNN-CVE-2025-64095-Upload-Block",
    "priority": 5,
    "ruleType": "MatchRule",
    "matchConditions": [{
      "matchVariables": [{"variableName": "RequestUri"}],
      "operator": "Regex",
      "matchValues": ["/(DesktopModules|Providers)/.*(Upload|FileManager|CKEditor)/"]
    }],
    "action": "Block"
  }]
}

3) IIS URL Rewrite & Request Filtering

For most DNN installs (Windows/IIS), add these temporary rules at the site level until patched.

web.config — URL Rewrite

<rule name="Block DNN Upload Endpoints (CVE-2025-64095)" stopProcessing="true">
  <match url="(DesktopModules|Providers)/.*(Upload|FileManager|CKEditor)/" ignoreCase="true" />
  <conditions>
    <add input="{REQUEST_METHOD}" pattern="POST" />
    <add input="{LOGON_USER}" pattern="^$" /> <!-- anonymous -->
  </conditions>
  <action type="CustomResponse" statusCode="403" statusReason="Forbidden" statusDescription="Blocked by security policy" />
</rule>

Request Filtering — Block Dangerous Upload Extensions

<requestFiltering>
  <fileExtensions>
    <add fileExtension=".aspx" allowed="false" />
    <add fileExtension=".ashx" allowed="false" />
    <add fileExtension=".config" allowed="false" />
    <add fileExtension=".dll" allowed="false" />
    <add fileExtension=".exe" allowed="false" />
    <add fileExtension=".ps1" allowed="false" />
  </fileExtensions>
</requestFiltering>

4) Incident Hunts — IIS Log Queries

Start with the server that hosts /Portals/ and editor providers.

# Suspicious anonymous POSTs to editor/upload endpoints (Kusto / Log Analytics)
W3CIISLog
| where csMethod == "POST"
| where csUriStem matches regex @"(DesktopModules|Providers)/.*(Upload|FileManager|CKEditor)/"
| where csUsername == "-"  // anonymous
| summarize count() by cIp, csUriStem, bin(TimeGenerated, 1h)
| order by count_ desc

# Overwrite attempts: 200 on image path after POST from same IP within 2 min
let suspect = W3CIISLog
| where csMethod == "POST" and csUriStem has_any ("Upload","FileManager","CKEditor")
| project cIp, ts=TimeGenerated;
W3CIISLog
| where csMethod == "GET" and csUriStem has "/Portals/"
| join kind=inner (suspect) on cIp
| where TimeGenerated between (ts .. ts + 2m) and scStatus == 200
| project TimeGenerated, cIp, csUriStem

5) Safe Patching Scripts (PowerShell) to 10.1.1+

Official fix: upgrade to DNN 10.1.1 or later. Validate from the vendor advisory / CVE.

Always snapshot/backup first. Test on staging. The script below backs up site & DB, restores on failure, then deploys updated files.

PowerShell — Backup & In-Place Update Skeleton (Windows/IIS)

# VARIABLES (edit)
$SiteRoot = "C:\inetpub\wwwroot\DNN"
$BackupDir = "D:\Backups\DNN_$(Get-Date -Format yyyyMMdd_HHmm)"
$AppPool = "DNN-AppPool"
$DbName  = "DNN_DB"
$SqlInst = ".\SQLEXPRESS"
$ZipPath = "D:\Packages\DNN_Platform_10.1.1.zip"   # vendor package

# 1) Prep
New-Item -ItemType Directory -Force -Path $BackupDir | Out-Null
Import-Module WebAdministration

# 2) Quiesce site
Stop-WebAppPool -Name $AppPool

# 3) Full backup (files + DB)
robocopy $SiteRoot "$BackupDir\site" /MIR /R:1 /W:1 | Out-Null
sqlcmd -S $SqlInst -Q "BACKUP DATABASE [$DbName] TO DISK='$BackupDir\dnn_db.bak' WITH INIT"

# 4) Deploy updated package (preserve web.config, connection strings)
Expand-Archive -Path $ZipPath -DestinationPath "$BackupDir\pkg" -Force
Copy-Item "$BackupDir\pkg\*" $SiteRoot -Recurse -Force -Exclude web.config

# 5) Start site and warmup
Start-WebAppPool -Name $AppPool
Invoke-WebRequest "https://your-dnn-site.example/" -UseBasicParsing | Out-Null

# 6) Basic health check (page contains DNN marker)
$resp = Invoke-WebRequest "https://your-dnn-site.example/" -UseBasicParsing
if ($resp.Content -notmatch "DNN") {
  Write-Warning "Post-update check failed — rolling back..."
  Stop-WebAppPool -Name $AppPool
  robocopy "$BackupDir\site" $SiteRoot /MIR /R:1 /W:1 | Out-Null
  sqlcmd -S $SqlInst -Q "RESTORE DATABASE [$DbName] FROM DISK='$BackupDir\dnn_db.bak' WITH REPLACE"
  Start-WebAppPool -Name $AppPool
}

If you use DNN upgrade packages that run an updater, insert those steps between 4–5. Validate permissions on /Install paths only during maintenance window.

6) Post-Patch Hardening Checklist

Disable public editor upload endpoints unless necessary; restrict to authenticated roles only.
Lock media paths: deny execution in /Portals/*; serve static only; block .aspx/.ashx/.config/.dll/.ps1.
Turn on anti-defacement monitors: file integrity watch for themes, /Portals, and default pages.
Log & alert: 403 spikes on upload paths; sudden 200s to modified images; admin logins from new ASNs.
Rollup other 2025 DNN fixes (IP filter bypass pre-10.0.1, editor OOB upload CVE-2025-62802, Prompt XSS pre-10.1.0).

FAQ

Is exploitation seen in the wild?

Public advisories rate the issue as critical with unauthenticated impact. Treat internet-facing DNN as exposed and patch promptly.

Which exact version fixes it?

DNN 10.1.1 resolves the unauthenticated upload/overwrite flaw; upgrade beyond that if available.

Will WAF rules alone make us safe?

No. WAF helps break the kill chain, but you must patch. Keep upload paths restricted and block script execution in media directories.

Sources

DNN GitHub Advisory — “Image Upload allows for Site Content Overwrite” (CVE-2025-64095).
MITRE CVE Record — CVE-2025-64095.
Tenable / CIRCL summaries — fixed in 10.1.1; unauthenticated upload & overwrite.
Wiz vulnerability digest & industry coverage on CVE-2025-64095.
Related 2025 DNN vulns: CVE-2025-62802, CVE-2025-59545, IP filter bypass.

CyberDudeBivash — Services, Apps & Ecosystem

DNN Hardening & Upgrade Sprints (10.1.1+ rollouts, zero-downtime plans, WAF tuning)
Detection Engineering (IIS log analytics, defacement early-warning, upload path telemetry)
Incident Response (clean restore, IOCs hunt, file integrity recovery)

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