CVE-2021-2433
📋 TL;DR
This vulnerability in Oracle Essbase Analytic Provider Services allows unauthenticated attackers to cause a denial of service (DoS) by crashing or hanging the service via HTTP requests. It affects versions 11.1.2.4 and 21.2 of the product. Organizations running these versions with network-accessible instances are at risk.
💻 Affected Systems
- Oracle Essbase Analytic Provider Services
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete unavailability of Essbase Analytic Provider Services, disrupting all dependent analytics and business intelligence operations until service restoration.
Likely Case
Service disruption causing temporary unavailability of analytics services, potentially affecting business reporting and decision-making processes.
If Mitigated
Limited impact if service is behind proper network segmentation and access controls, with minimal disruption to isolated systems.
🎯 Exploit Status
CVSS indicates 'easily exploitable' with no authentication required, suggesting simple HTTP requests can trigger the DoS condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply Critical Patch Update for July 2021 or later
Vendor Advisory: https://www.oracle.com/security-alerts/cpujul2021.html
Restart Required: Yes
Instructions:
1. Download the appropriate Critical Patch Update from Oracle Support. 2. Apply the patch following Oracle's Essbase patching procedures. 3. Restart the Essbase Analytic Provider Services. 4. Verify the patch was successfully applied.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict network access to Essbase Analytic Provider Services to only trusted IP addresses/networks
Use firewall rules to limit access: iptables -A INPUT -p tcp --dport <essbase_port> -s <trusted_ip> -j ACCEPT
iptables -A INPUT -p tcp --dport <essbase_port> -j DROP
Web Application Firewall
allDeploy WAF to filter malicious HTTP requests before they reach the vulnerable service
🧯 If You Can't Patch
- Implement strict network access controls to limit HTTP access to only necessary systems
- Monitor service availability and implement rapid response procedures for potential DoS incidents
🔍 How to Verify
Check if Vulnerable:
Check Essbase version: If running 11.1.2.4 or 21.2, the system is vulnerable. Verify network accessibility to the HTTP service.Check Version:
Check Essbase installation logs or use Oracle-provided version checking utilities specific to your deploymentVerify Fix Applied:
Check that Critical Patch Update for July 2021 or later is applied. Test service functionality and attempt to trigger the DoS condition (in controlled environment).📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP request patterns to Essbase Web Services
- Service crash or restart events in Essbase logs
- Increased error rates in application logs
Network Indicators:
- Spike in HTTP traffic to Essbase ports from unauthenticated sources
- Repeated connection attempts followed by service unavailability
SIEM Query:
source="essbase_logs" AND (event="crash" OR event="hang" OR event="restart") OR (http_request_count > threshold AND destination_port=<essbase_port>)