CVE-2023-50090
📋 TL;DR
This vulnerability allows attackers to write arbitrary files to the server through a crafted POST request to the saveReportFile method in ureport2. Successful exploitation could lead to remote code execution, affecting all systems running ureport2 version 2.2.9 and earlier.
💻 Affected Systems
- ureport2
📦 What is this software?
Ureport2 by Ureport2 Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining remote code execution, data theft, and persistent backdoor installation.
Likely Case
Arbitrary file write leading to web shell deployment and subsequent command execution.
If Mitigated
File write limited to web-accessible directories without execution privileges.
🎯 Exploit Status
Public exploit details available in referenced advisories showing simple POST request exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2.10 or later
Vendor Advisory: https://github.com/advisories/GHSA-445x-c8qq-qfr9
Restart Required: Yes
Instructions:
1. Download ureport2 version 2.2.10 or later from official repository. 2. Replace existing ureport2 JAR files with patched version. 3. Restart the application server.
🔧 Temporary Workarounds
Input Validation Filter
allImplement web application firewall or filter to block malicious POST requests to saveReportFile endpoint.
# Configure WAF rule to block POST requests containing file path traversal patterns
# Example ModSecurity rule: SecRule ARGS "\.\./" "id:1001,phase:2,deny"
Access Restriction
allRestrict access to ureport2 endpoints using network controls or authentication.
# Apache .htaccess example: Order deny,allow
Deny from all
Allow from 192.168.1.0/24
# Nginx location block: location /ureport2/ { deny all; }
🧯 If You Can't Patch
- Isolate ureport2 instance behind strict network segmentation with no internet access.
- Implement application-level input validation to sanitize file path parameters in POST requests.
🔍 How to Verify
Check if Vulnerable:
Check ureport2 version in application configuration or JAR file metadata. If version ≤2.2.9, system is vulnerable.Check Version:
java -jar ureport2-core-*.jar --version OR check MANIFEST.MF in JAR fileVerify Fix Applied:
Confirm ureport2 version is 2.2.10 or later and test that crafted POST requests to saveReportFile endpoint are rejected.📡 Detection & Monitoring
Log Indicators:
- POST requests to /ureport2/saveReportFile with unusual file paths
- File write operations to unexpected locations
- Web shell creation in web directories
Network Indicators:
- HTTP POST requests with path traversal sequences (../) to ureport2 endpoints
- Unusual outbound connections from ureport2 server
SIEM Query:
source="web_logs" AND uri="/ureport2/saveReportFile" AND (method="POST" AND (body CONTAINS "../" OR body CONTAINS "/etc/" OR body CONTAINS "/tmp/"))