CVE-2024-26091
📋 TL;DR
This DOM-based Cross-Site Scripting vulnerability in Adobe Experience Manager allows attackers to execute malicious JavaScript in victims' browsers by tricking them into clicking malicious links or submitting forms. It affects AEM versions 6.5.20 and earlier. Successful exploitation could lead to session hijacking, data theft, or unauthorized actions within the victim's permissions.
💻 Affected Systems
- Adobe Experience Manager
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full control of victim's AEM session, leading to data theft, privilege escalation, content manipulation, or complete system compromise if victim has administrative privileges.
Likely Case
Session hijacking leading to unauthorized content access or modification, credential theft via phishing, or defacement of web content.
If Mitigated
Limited impact due to user interaction requirement and potential Content Security Policy protections, possibly resulting in minor data exposure.
🎯 Exploit Status
Exploitation requires user interaction (clicking malicious link or submitting form). No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.5.21 or later
Vendor Advisory: https://helpx.adobe.com/security/products/experience-manager/apsb24-28.html
Restart Required: Yes
Instructions:
1. Download AEM 6.5.21 or later from Adobe's distribution portal. 2. Apply the service pack following Adobe's upgrade documentation. 3. Restart the AEM instance. 4. Verify the update was successful.
🔧 Temporary Workarounds
Implement Content Security Policy
allDeploy a strict Content Security Policy to prevent execution of inline scripts and restrict script sources.
Add 'Content-Security-Policy' header with appropriate directives for your environment
Input Validation and Output Encoding
allImplement server-side validation and proper output encoding for all user inputs.
Configure AEM's XSS protection filters and validate all form inputs
🧯 If You Can't Patch
- Implement Web Application Firewall (WAF) rules to detect and block XSS payloads
- Restrict user permissions and implement principle of least privilege
🔍 How to Verify
Check if Vulnerable:
Check AEM version via the Welcome screen or OSGi console. If version is 6.5.20 or earlier, the system is vulnerable.Check Version:
Check AEM Welcome page or use CRXDE Lite to view version informationVerify Fix Applied:
Verify AEM version is 6.5.21 or later and test XSS payloads to confirm they are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript execution patterns
- Suspicious URL parameters containing script tags
- Multiple failed XSS attempts
Network Indicators:
- Requests with suspicious parameters containing JavaScript
- Unusual referrer headers with encoded payloads
SIEM Query:
source="aem_access.log" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")