CVE-2021-27630
📋 TL;DR
CVE-2021-27630 is a denial-of-service vulnerability in SAP NetWeaver ABAP Server and ABAP Platform Enqueue Server. An unauthenticated attacker can send a specially crafted network packet to crash the system, making it unavailable. This affects organizations running vulnerable SAP NetWeaver versions.
💻 Affected Systems
- SAP NetWeaver ABAP Server
- SAP NetWeaver ABAP Platform
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system outage of SAP services, disrupting business operations that depend on SAP applications.
Likely Case
Service disruption affecting availability of SAP systems, potentially causing operational downtime.
If Mitigated
Limited impact if systems are patched, network-restricted, or behind firewalls with proper filtering.
🎯 Exploit Status
Exploitation requires network access to the Enqueue Server port (typically 3200-3299). No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply SAP Security Note 3020104
Vendor Advisory: https://launchpad.support.sap.com/#/notes/3020104
Restart Required: Yes
Instructions:
1. Download SAP Note 3020104 from SAP Support Portal. 2. Apply kernel patch according to SAP standard procedures. 3. Restart affected SAP systems.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to Enqueue Server ports (3200-3299) to trusted sources only.
Firewall Rules
allImplement firewall rules to block unauthorized access to SAP Enqueue Server ports.
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach SAP Enqueue Server ports.
- Monitor system logs for crash events and implement rapid response procedures for potential DoS incidents.
🔍 How to Verify
Check if Vulnerable:
Check SAP kernel version using transaction SM51 or OS command 'disp+work'.Check Version:
On SAP system: Execute transaction SM51 or run 'disp+work -version' from OS command line.Verify Fix Applied:
Verify SAP Note 3020104 is applied by checking applied notes in SAP system or kernel patch level.📡 Detection & Monitoring
Log Indicators:
- System crash logs
- Enqueue Server termination events
- ABAP dumps related to EnqConvUniToSrvReq()
Network Indicators:
- Unusual traffic to Enqueue Server ports (3200-3299)
- Malformed packets to SAP services
SIEM Query:
Search for: 'Enqueue Server crash' OR 'ABAP dump' OR 'system termination' in SAP logs