CVE-2020-28149
📋 TL;DR
CVE-2020-28149 is a cross-site scripting vulnerability in myDBR reporting software that allows attackers to inject malicious scripts via CSRF tokens. This enables remote code execution in the context of the victim's browser session. Organizations using myDBR 5.8.3/4262 are affected.
💻 Affected Systems
- myDBR
📦 What is this software?
Mydbr by Mydbr
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of user sessions, data theft, and potential lateral movement within the organization's network through browser-based attacks.
Likely Case
Session hijacking, credential theft, and unauthorized access to sensitive reporting data within myDBR.
If Mitigated
Limited impact with proper input validation and output encoding, though some data exposure may still occur.
🎯 Exploit Status
Exploitation requires user interaction (clicking a malicious link) but the XSS payload execution is straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.8.4 or later
Vendor Advisory: https://c41nc.co.uk/cve-2020-28149/
Restart Required: Yes
Instructions:
1. Download latest myDBR version from official source. 2. Backup current installation. 3. Apply update following vendor instructions. 4. Restart myDBR services.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for CSRF tokens to reject malicious payloads
Implement server-side validation: if (!preg_match('/^[a-zA-Z0-9]+$/', $csrf_token)) { reject_request(); }
Content Security Policy
allImplement CSP headers to restrict script execution sources
Header set Content-Security-Policy "script-src 'self'"
Header set X-Content-Type-Options "nosniff"
🧯 If You Can't Patch
- Implement WAF rules to block XSS payloads in CSRF token parameters
- Restrict network access to myDBR instances to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check myDBR version in admin interface or configuration files. If version is 5.8.3/4262, system is vulnerable.Check Version:
Check myDBR web interface admin panel or examine version.txt in installation directoryVerify Fix Applied:
Verify version is 5.8.4 or later and test CSRF token handling with XSS payloads.📡 Detection & Monitoring
Log Indicators:
- Unusual length CSRF tokens
- CSRF tokens containing script tags or JavaScript patterns
- Multiple failed CSRF validation attempts
Network Indicators:
- HTTP requests with suspicious parameters in CSRF token fields
- External domains loading in myDBR context
SIEM Query:
source="myDBR" AND (csrftoken="*<script>*" OR csrftoken="*javascript:*" OR csrftoken LENGTH > 100)