CVE-2023-46304
📋 TL;DR
CVE-2023-46304 is a remote code execution vulnerability in Vtiger CRM 7.5.0 where authenticated attackers can write arbitrary PHP code to config.inc.php, which executes on every page load. This allows attackers to execute commands on the server with the web server's privileges. All Vtiger CRM 7.5.0 installations with authenticated user access are affected.
💻 Affected Systems
- Vtiger CRM
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, steal sensitive data, install backdoors, pivot to internal networks, and maintain persistent access.
Likely Case
Attackers gain shell access to the web server, exfiltrate CRM data including customer information and business records, and potentially use the server for further attacks.
If Mitigated
Limited impact with proper network segmentation, minimal privileges, and monitoring catching exploitation attempts early.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained. Public proof-of-concept code exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in commit 317f9ca88b6bbded11058f20a1d232717c360d43
Vendor Advisory: https://code.vtiger.com/vtiger/vtigercrm/-/commit/317f9ca88b6bbded11058f20a1d232717c360d43
Restart Required: No
Instructions:
1. Update to the latest Vtiger CRM version. 2. Apply the specific patch from commit 317f9ca88b6bbded11058f20a1d232717c360d43. 3. Verify the Module.php file no longer contains the vulnerable code path.
🔧 Temporary Workarounds
Restrict access to vulnerable endpoint
allUse web application firewall or server configuration to block access to the vulnerable Users module endpoint.
# Apache: RewriteRule ^modules/Users/models/Module\.php$ - [F]
# Nginx: location ~ ^/modules/Users/models/Module\.php$ { deny all; }
File permissions hardening
linuxSet config.inc.php to read-only for the web server user to prevent modification.
chmod 444 config.inc.php
chown root:root config.inc.php
🧯 If You Can't Patch
- Implement strict access controls and monitoring for authenticated users
- Isolate the Vtiger CRM instance in a segmented network with limited outbound access
🔍 How to Verify
Check if Vulnerable:
Check if running Vtiger CRM 7.5.0 and examine modules/Users/models/Module.php for the vulnerable code pattern allowing file writes to config.inc.php.Check Version:
Check Vtiger CRM version in the admin panel or examine version files in the installation directory.Verify Fix Applied:
Verify the Module.php file has been updated with the patch from commit 317f9ca88b6bbded11058f20a1d232717c360d43 and test that authenticated users cannot write to config.inc.php.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to modules/Users/models/Module.php
- Unexpected modifications to config.inc.php file
- Web server errors related to PHP execution failures
Network Indicators:
- HTTP requests with PHP code in parameters targeting the Users module
- Outbound connections from the web server to unexpected destinations
SIEM Query:
source="web_server" AND (uri="/modules/Users/models/Module.php" OR file_path="config.inc.php") AND (method="POST" OR action="write" OR status="200")🔗 References
- https://code.vtiger.com/vtiger/vtigercrm/-/blob/master/modules/Users/models/Module.php
- https://code.vtiger.com/vtiger/vtigercrm/-/commit/317f9ca88b6bbded11058f20a1d232717c360d43
- https://github.com/jselliott/CVE-2023-46304
- https://www.vtiger.com/
- https://code.vtiger.com/vtiger/vtigercrm/-/blob/master/modules/Users/models/Module.php
- https://code.vtiger.com/vtiger/vtigercrm/-/commit/317f9ca88b6bbded11058f20a1d232717c360d43
- https://github.com/jselliott/CVE-2023-46304
- https://www.vtiger.com/
