CVE-2025-21547
📋 TL;DR
This vulnerability in Oracle Hospitality OPERA 5 allows unauthenticated attackers with network access via HTTP to access sensitive data or cause denial of service. Affected systems include OPERA 5 versions 5.6.19.20, 5.6.25.8, 5.6.26.6, and 5.6.27.1.
💻 Affected Systems
- Oracle Hospitality OPERA 5
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all OPERA 5 accessible data and complete system crash causing extended downtime
Likely Case
Unauthorized access to sensitive guest and operational data followed by service disruption
If Mitigated
Limited impact if network segmentation and access controls prevent HTTP access from untrusted networks
🎯 Exploit Status
CVSS indicates 'easily exploitable' with no authentication required
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Oracle's January 2025 Critical Patch Update for specific fixed versions
Vendor Advisory: https://www.oracle.com/security-alerts/cpujan2025.html
Restart Required: Yes
Instructions:
1. Review Oracle's January 2025 Critical Patch Update advisory 2. Apply the appropriate patch for your OPERA 5 version 3. Restart the OPERA 5 service 4. Verify the patch was successfully applied
🔧 Temporary Workarounds
Network Segmentation
allRestrict HTTP access to OPERA 5 to only trusted networks and IP addresses
Web Application Firewall
allDeploy WAF with rules to block suspicious HTTP requests to OPERA 5 endpoints
🧯 If You Can't Patch
- Implement strict network access controls to limit HTTP access to OPERA 5
- Monitor for unusual HTTP traffic patterns and failed authentication attempts
🔍 How to Verify
Check if Vulnerable:
Check OPERA 5 version against affected versions listCheck Version:
Check OPERA 5 administration interface or configuration files for version informationVerify Fix Applied:
Verify version is updated beyond affected versions and test HTTP functionality📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to Opera Servlet endpoints
- Multiple failed authentication attempts
- System crash or hang events
Network Indicators:
- Unusual HTTP traffic patterns to OPERA 5 ports
- Requests from unexpected source IPs
SIEM Query:
source="opera5" AND (http.status=500 OR http.method=POST AND http.uri contains "/servlet")