CVE-2025-57876
📋 TL;DR
A stored cross-site scripting vulnerability in Esri Portal for ArcGIS 11.4 and earlier allows authenticated attackers with high privileges to inject malicious files containing JavaScript. When victims load these files, arbitrary code executes in their browsers, potentially disclosing privileged tokens. This affects organizations using vulnerable versions of Esri Portal for ArcGIS.
💻 Affected Systems
- Esri Portal for ArcGIS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full administrative control of the Portal by stealing privileged tokens, leading to complete system compromise and data exfiltration.
Likely Case
Attacker steals session tokens or credentials from authenticated users, enabling privilege escalation and unauthorized access to sensitive portal data.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized, preventing code execution and token theft.
🎯 Exploit Status
Exploitation requires authentication with high privileges and victim interaction to load malicious file.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply Security 2025 Update 3 Patch
Vendor Advisory: https://www.esri.com/arcgis-blog/products/trust-arcgis/administration/portal-for-arcgis-security-2025-update-3-patch
Restart Required: No
Instructions:
1. Download Security 2025 Update 3 patch from Esri. 2. Apply patch to all affected Portal instances. 3. Verify patch installation via version check.
🔧 Temporary Workarounds
Restrict File Uploads
allTemporarily disable or restrict file upload functionality for non-administrative users.
Implement Content Security Policy
allDeploy CSP headers to restrict script execution from untrusted sources.
🧯 If You Can't Patch
- Implement strict input validation and output encoding for file uploads.
- Monitor and audit file upload activities for suspicious patterns.
🔍 How to Verify
Check if Vulnerable:
Check Portal version via administrative interface; if version is 11.4 or earlier, system is vulnerable.Check Version:
Check via Portal administrative console or Esri diagnostic tools.Verify Fix Applied:
Confirm Portal version is updated post-patch; test file upload functionality with XSS payloads to ensure neutralization.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads with script-like content
- Multiple failed upload attempts from single user
Network Indicators:
- HTTP requests with malicious script patterns in file uploads
SIEM Query:
source="portal_logs" AND (file_upload AND (javascript OR script))