CVE-2024-20769
📋 TL;DR
This stored Cross-Site Scripting (XSS) vulnerability in Adobe Experience Manager allows attackers to inject malicious JavaScript into vulnerable form fields. When users visit pages containing these compromised fields, their browsers execute the attacker's scripts. This affects Adobe Experience Manager versions 6.5.20 and earlier.
💻 Affected Systems
- Adobe Experience Manager
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal user session cookies, perform actions as authenticated users, redirect to malicious sites, or install malware on victim systems.
Likely Case
Session hijacking, credential theft, or defacement of web pages through injected content.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, though stored XSS remains dangerous.
🎯 Exploit Status
XSS vulnerabilities are commonly exploited and require attacker access to vulnerable form fields. The stored nature makes exploitation more reliable once initial access is achieved.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Adobe Experience Manager 6.5.21 or later
Vendor Advisory: https://helpx.adobe.com/security/products/experience-manager/apsb24-28.html
Restart Required: Yes
Instructions:
1. Download Adobe Experience Manager 6.5.21 or later from Adobe's official distribution channels. 2. Follow Adobe's upgrade documentation for your deployment type (on-premise or cloud). 3. Apply the update to all affected instances. 4. Restart the AEM service. 5. Verify the update was successful.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and output encoding for all user-controllable form fields
Implement Content Security Policy (CSP) headers
Use OWASP Java Encoder for output encoding
Configure input validation filters
Temporary Form Field Restrictions
allDisable or restrict vulnerable form fields until patching can be completed
Modify form configurations to remove vulnerable fields
Implement additional authentication for form submissions
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to limit script execution
- Deploy a Web Application Firewall (WAF) with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check Adobe Experience Manager version via AEM Web Console (/system/console) or by examining the CRX package managerCheck Version:
Check via AEM Web Console at /system/console or examine the crx-quickstart folder for version informationVerify Fix Applied:
Verify version is 6.5.21 or later and test form fields with XSS payloads to ensure proper sanitization📡 Detection & Monitoring
Log Indicators:
- Unusual form submissions with script tags
- Multiple failed XSS attempts in access logs
- Suspicious content in repository nodes
Network Indicators:
- HTTP requests containing script injection patterns
- Unusual outbound connections from AEM servers
SIEM Query:
source="aem_access.log" AND ("<script" OR "javascript:" OR "onerror=" OR "onload=")