CVE-2011-1028
📋 TL;DR
This vulnerability in Smarty3 allows remote attackers to execute arbitrary PHP code through the $smarty.template variable. It affects web applications using vulnerable versions of the Smarty template engine. Attackers can potentially take full control of affected systems.
💻 Affected Systems
- Smarty Template Engine
📦 What is this software?
Smarty by Smarty
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise leading to data theft, ransomware deployment, or creation of persistent backdoors.
Likely Case
Web server compromise allowing data exfiltration, defacement, or lateral movement within the network.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, though risk remains.
🎯 Exploit Status
Exploitation requires access to template rendering functionality but is straightforward once that access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Smarty 3.0.8 and later
Vendor Advisory: https://github.com/smarty-php/smarty/security/advisories
Restart Required: No
Instructions:
1. Update Smarty to version 3.0.8 or later. 2. Replace the smarty directory with the patched version. 3. Clear any template caches. 4. Test application functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for all template variables before processing.
// PHP code to validate $smarty.template variable
if (!preg_match('/^[a-zA-Z0-9_\-\.\/]+$/', $smarty->template)) {
die('Invalid template name');
}
🧯 If You Can't Patch
- Implement WAF rules to block suspicious template variable patterns
- Restrict access to template rendering functionality to authenticated users only
🔍 How to Verify
Check if Vulnerable:
Check Smarty version in your application's vendor directory or composer.json for version < 3.0.8Check Version:
grep -r 'smarty' composer.json || find . -name '*.php' -exec grep -l 'Smarty' {} \; | head -5Verify Fix Applied:
Confirm Smarty version is 3.0.8 or higher and test template functionality📡 Detection & Monitoring
Log Indicators:
- Unusual PHP execution errors
- Suspicious template file access patterns
- Unexpected system command execution in web logs
Network Indicators:
- Unusual outbound connections from web server
- HTTP requests with suspicious template parameters
SIEM Query:
source="web_logs" AND ("$smarty.template" OR "smarty_internal_compile") AND status=500🔗 References
- https://access.redhat.com/security/cve/cve-2011-1028
- https://seclists.org/oss-sec/2011/q1/313
- https://security-tracker.debian.org/tracker/CVE-2011-1028
- https://access.redhat.com/security/cve/cve-2011-1028
- https://seclists.org/oss-sec/2011/q1/313
- https://security-tracker.debian.org/tracker/CVE-2011-1028
