CVE-2023-49214
📋 TL;DR
CVE-2023-49214 is a chat template injection vulnerability in Usedesk that allows attackers to inject malicious templates into chat interfaces. This affects all Usedesk instances running versions before 1.7.57, potentially compromising customer support systems and exposing sensitive data.
💻 Affected Systems
- Usedesk
📦 What is this software?
Usedesk by Usedesk
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing remote code execution, data exfiltration, and lateral movement within the network.
Likely Case
Cross-site scripting attacks, session hijacking, and unauthorized access to customer support data and conversations.
If Mitigated
Limited impact with proper input validation and output encoding, potentially only minor UI manipulation.
🎯 Exploit Status
Template injection vulnerabilities typically have low exploitation complexity and can be exploited without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.7.57
Vendor Advisory: https://usedesk.ru/updates_september23
Restart Required: Yes
Instructions:
1. Backup your Usedesk instance and database. 2. Download version 1.7.57 or later from the official Usedesk website. 3. Follow the official upgrade instructions provided by Usedesk. 4. Restart the Usedesk service. 5. Verify the upgrade was successful.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for all chat template fields to reject potentially malicious content.
Implement server-side validation: if (containsMaliciousPattern(input)) { rejectInput(); }
Output Encoding
allApply proper output encoding when rendering chat templates to prevent injection.
Use HTML entity encoding: htmlspecialchars($template, ENT_QUOTES, 'UTF-8');
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with rules to detect and block template injection attempts.
- Isolate the Usedesk instance in a segmented network with strict access controls and monitoring.
🔍 How to Verify
Check if Vulnerable:
Check the Usedesk version in the admin panel or configuration files. If version is below 1.7.57, the system is vulnerable.Check Version:
Check admin panel or configuration file for version number.Verify Fix Applied:
After patching, verify the version shows 1.7.57 or higher in the admin interface.📡 Detection & Monitoring
Log Indicators:
- Unusual template modifications
- Suspicious chat payloads containing script tags or template syntax
- Multiple failed template validation attempts
Network Indicators:
- HTTP requests with unusual template parameters
- Requests containing malicious payload patterns in chat endpoints
SIEM Query:
source="usedesk" AND (template="*<script>*" OR template="*{{*" OR template="*%7B%7B*")