CVE-2023-25835
📋 TL;DR
A stored XSS vulnerability in Esri Portal for ArcGIS Sites allows authenticated high-privilege attackers to inject malicious JavaScript into site configurations. When victims access compromised links, attackers can steal sensitive data, manipulate site content, and disrupt functionality. This affects versions 11.1 and below of Esri Portal for ArcGIS Sites.
💻 Affected Systems
- Esri Portal for ArcGIS Sites
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full control over victim sessions, steal all accessible user data, completely compromise site integrity, and cause permanent service disruption.
Likely Case
Attackers steal session cookies and user data, modify site content to spread malware or phishing, and cause temporary service interruptions.
If Mitigated
Limited impact with proper access controls, network segmentation, and monitoring detecting anomalous configuration changes.
🎯 Exploit Status
Exploitation requires authenticated high-privilege access but is technically simple once access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply security patch for versions 11.1 and below
Vendor Advisory: https://www.esri.com/arcgis-blog/products/trust-arcgis/administration/portal-for-arcgis-enterprise-sites-security-patch-is-now-available/
Restart Required: Yes
Instructions:
1. Download security patch from Esri support. 2. Apply patch following Esri's installation guide. 3. Restart Portal services. 4. Verify patch application.
🔧 Temporary Workarounds
Restrict High-Privilege Access
allLimit administrative access to only essential personnel and implement strict access controls.
Implement Content Security Policy
allDeploy CSP headers to restrict script execution from unauthorized sources.
🧯 If You Can't Patch
- Implement strict input validation and output encoding for all user-controlled data in site configurations.
- Deploy web application firewall rules to block XSS payload patterns and monitor for exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check Portal version via administrative interface; if version is 11.1 or below, system is vulnerable.Check Version:
Check via Portal web interface or administrative console for version information.Verify Fix Applied:
Verify patch installation through Portal version check and test for XSS payload execution in site configuration fields.📡 Detection & Monitoring
Log Indicators:
- Unusual configuration changes by high-privilege users
- JavaScript payloads in site configuration logs
- Multiple failed XSS attempts
Network Indicators:
- Unexpected JavaScript execution in browser sessions
- Anomalous outbound data transfers following configuration access
SIEM Query:
source="portal_logs" AND (event="configuration_change" AND user_privilege="high") OR (message CONTAINS "script" OR "javascript")