CVE-2020-9732
📋 TL;DR
This stored XSS vulnerability in Adobe Experience Manager Forms allows authenticated users with 'Author' privileges to inject malicious scripts into Sites component fields. When other users view pages containing these fields, the scripts execute in their browsers, potentially compromising their sessions or systems. Affects AEM Forms add-on versions 6.5.5.0 and below, and 6.4.8.2 and below.
💻 Affected Systems
- Adobe Experience Manager Forms add-on
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers with author access could steal administrator credentials, perform session hijacking, deface websites, or deliver malware to all users visiting compromised pages.
Likely Case
Malicious authors inject scripts to steal session cookies or credentials from other users, leading to unauthorized access and potential data theft.
If Mitigated
With proper input validation and output encoding, scripts are treated as text rather than executable code, preventing browser execution.
🎯 Exploit Status
Exploitation requires authenticated access with Author privileges. Stored XSS payloads persist until removed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: AEM Forms 6.5.6.0 and 6.4.8.3
Vendor Advisory: https://helpx.adobe.com/security/products/experience-manager/apsb20-56.html
Restart Required: Yes
Instructions:
1. Download appropriate AEM Forms service pack from Adobe Distribution portal. 2. Apply service pack using Package Manager. 3. Restart AEM instance. 4. Verify installation via Package Manager console.
🔧 Temporary Workarounds
Input Validation Filter
allImplement custom servlet filter to sanitize input in Sites component fields
Implement custom Java filter extending javax.servlet.Filter with XSS sanitization logic
Content Security Policy
allImplement strict CSP headers to restrict script execution
Add 'Content-Security-Policy: script-src 'self'' to HTTP response headers
🧯 If You Can't Patch
- Restrict Author privileges to trusted users only
- Implement web application firewall with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check AEM Forms version via Package Manager or CRXDE Lite. If version is 6.5.5.0 or below, or 6.4.8.2 or below, system is vulnerable.Check Version:
curl -u admin:password http://localhost:4502/system/console/status-productinfo.json | grep 'AEM Forms'Verify Fix Applied:
After patching, verify version shows 6.5.6.0 or higher, or 6.4.8.3 or higher. Test XSS payload injection in Sites component fields to confirm sanitization.📡 Detection & Monitoring
Log Indicators:
- Unusual content modifications by Author users
- Script tags or JavaScript in content repository entries
Network Indicators:
- Unexpected script loads from AEM pages
- Suspicious outbound connections from user browsers
SIEM Query:
source="aem-audit.log" AND (event="content-modified" AND user="*author*" AND content="*script*" OR "javascript:")