CVE-2026-3725
📋 TL;DR
This CVE describes a Server-Side Template Injection (SSTI) vulnerability in SmartAdmin's email template rendering component. Attackers can inject malicious FreeMarker templates through the template_content parameter, potentially leading to remote code execution. Organizations using SmartAdmin up to version 3.29 are affected.
💻 Affected Systems
- 1024-lab/lab1024 SmartAdmin
📦 What is this software?
Smartadmin by Lab1024
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with application server privileges, allowing complete system compromise, data exfiltration, and lateral movement.
Likely Case
Arbitrary file read/write, sensitive information disclosure, and potential privilege escalation within the application context.
If Mitigated
Limited impact due to proper input validation and sandboxing, potentially only causing template rendering errors.
🎯 Exploit Status
Exploit details have been published and the vulnerability is in a template engine, making weaponization straightforward for attackers with basic SSTI knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
1. Monitor the official SmartAdmin repository for security updates. 2. Upgrade to a version beyond 3.29 when available. 3. Restart the application after patching.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation for template_content parameter to reject FreeMarker expressions
Disable Vulnerable Endpoint
allTemporarily disable or restrict access to the mail template rendering functionality
🧯 If You Can't Patch
- Implement WAF rules to block FreeMarker template injection patterns
- Restrict network access to the application and implement strict authentication requirements
🔍 How to Verify
Check if Vulnerable:
Check if SmartAdmin version is ≤3.29 and review if MailService's freemarkerResolverContent accepts user-controlled template_contentCheck Version:
Check application configuration or pom.xml for SmartAdmin versionVerify Fix Applied:
Test template injection attempts after implementing workarounds to ensure they are properly blocked📡 Detection & Monitoring
Log Indicators:
- Unusual FreeMarker template errors
- Suspicious template_content parameter values containing ${, <#assign, or @ expressions
- Multiple failed template rendering attempts
Network Indicators:
- HTTP requests to mail template endpoints with encoded FreeMarker payloads
- Unusual outbound connections from application server
SIEM Query:
source="application.log" AND ("freemarkerResolverContent" OR "template_content") AND ("${*" OR "<#*" OR "@*")