CVE-2021-27610
📋 TL;DR
This vulnerability in SAP NetWeaver ABAP Server and ABAP Platform allows improper authentication due to inconsistent formatting of RFC user information. Attackers could exploit this to gain unauthorized access to affected systems. All organizations running vulnerable SAP ABAP versions are affected.
💻 Affected Systems
- SAP NetWeaver ABAP Server
- SAP ABAP Platform
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to access sensitive business data, execute arbitrary code, and pivot to other systems in the network.
Likely Case
Unauthorized access to business-critical SAP systems leading to data theft, manipulation of business processes, or privilege escalation.
If Mitigated
Limited impact if strong network segmentation, monitoring, and additional authentication controls are implemented.
🎯 Exploit Status
Exploitation requires some knowledge of SAP RFC protocols but no public exploit code is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply SAP Security Note 3007182
Vendor Advisory: https://launchpad.support.sap.com/#/notes/3007182
Restart Required: Yes
Instructions:
1. Download SAP Note 3007182 from SAP Support Portal. 2. Apply the correction instructions provided in the note. 3. Restart affected SAP systems. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Restrict RFC Access
allLimit RFC connections to trusted systems only using SAP security profiles and network controls.
Configure SNC for RFC connections
Use transaction SM59 to restrict RFC destinations
Enhanced Monitoring
allImplement strict monitoring of RFC connections and authentication attempts.
Use transaction SMGW to monitor gateway logs
Enable detailed RFC logging
🧯 If You Can't Patch
- Implement strict network segmentation to isolate SAP systems from untrusted networks
- Enable multi-factor authentication for all SAP user accounts and monitor for suspicious RFC activity
🔍 How to Verify
Check if Vulnerable:
Check if SAP Security Note 3007182 is applied using transaction SNOTE or by checking system version against affected versions.Check Version:
Execute transaction SM51 or check system info in SAP GUIVerify Fix Applied:
Verify SAP Note 3007182 implementation status in transaction SNOTE and test RFC authentication scenarios.📡 Detection & Monitoring
Log Indicators:
- Unusual RFC connection patterns
- Failed authentication attempts from unexpected sources
- Multiple RFC login attempts from single source
Network Indicators:
- Unexpected RFC traffic to SAP systems
- RFC connections from unauthorized IP addresses
SIEM Query:
source="sap_gateway" AND (event_type="RFC_AUTH_FAILURE" OR event_type="RFC_CONNECTION_ATTEMPT")