CVE-2023-5965
📋 TL;DR
This vulnerability allows authenticated privileged attackers to upload malicious zip files to EspoCRM servers, leading to arbitrary PHP code execution. Attackers with administrative access can compromise the entire application server. Only EspoCRM version 7.2.5 is affected.
💻 Affected Systems
- EspoCRM
📦 What is this software?
Espocrm by Espocrm
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise with attacker gaining full control over the EspoCRM instance and potentially the underlying server, enabling data theft, ransomware deployment, or lateral movement.
Likely Case
Attacker uploads web shell or backdoor, establishing persistent access to steal sensitive CRM data, manipulate business processes, or use server for further attacks.
If Mitigated
With proper access controls and file upload restrictions, impact limited to authenticated admin users who would already have significant privileges.
🎯 Exploit Status
Exploitation requires admin credentials but is straightforward once authenticated; zip file manipulation is well-documented technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.2.6 or later
Vendor Advisory: https://www.espocrm.com/blog/security-update/
Restart Required: No
Instructions:
1. Backup your EspoCRM instance and database. 2. Download latest version from espocrm.com. 3. Replace existing installation files with patched version. 4. Clear cache via Administration > Clear Cache. 5. Verify functionality.
🔧 Temporary Workarounds
Restrict File Uploads
allTemporarily disable or restrict zip file uploads through the update form
Modify EspoCRM configuration to reject .zip uploads or implement file type validation
Admin Access Restriction
allLimit admin account access to trusted IP addresses only
Implement IP whitelisting for admin panel access in web server configuration
🧯 If You Can't Patch
- Implement strict access controls for admin accounts with MFA and monitor admin activity logs
- Deploy WAF rules to block suspicious file upload patterns and monitor for zip file upload attempts
🔍 How to Verify
Check if Vulnerable:
Check EspoCRM version in Administration > About; if version is exactly 7.2.5, system is vulnerable.Check Version:
Check EspoCRM admin panel or inspect version in /data/config.phpVerify Fix Applied:
Verify version is 7.2.6 or higher in Administration > About; test that zip uploads are properly validated.📡 Detection & Monitoring
Log Indicators:
- Unusual admin login patterns
- Zip file uploads via update form
- PHP file execution from unexpected locations
Network Indicators:
- POST requests with zip files to update endpoints
- Outbound connections from EspoCRM server to unknown IPs
SIEM Query:
source="espocrm" AND (file_extension=".zip" OR action="upload") AND user_role="admin"