SAP RFC
SAP RFC (Remote Function Call) is a proprietary protocol used to communicate and exchange data between SAP systems and external applications. It is critical for SAP security teams to secure these connections because misconfigured or over-privileged RFCs provide attackers with a direct pathway to execute operating system commands, extract sensitive data, and bypass application access controls. Securing this protocol requires continuous monitoring of interface traffic rather than relying solely on static firewall rules.
How to Secure SAP RFC Connections
Securing SAP RFC connections requires continuous monitoring of application-layer traffic to detect unauthorized remote executions. Relying on traditional perimeter defenses leaves interconnected business processes completely vulnerable to internal pivoting and lateral movement.
Prerequisites
- A complete inventory of all active RFC destinations and their associated user permissions.
- A specialized SAP threat detection platform capable of decoding proprietary SAP protocols.
- A baseline of normal, authorized machine-to-machine traffic.
The Remediation Workflow
- Connection Assessment: Scan the SAP landscape to identify all configured RFC destinations and flag any connections utilizing highly privileged accounts like SAP_ALL.
- Access Restriction: Enforce the principle of least privilege by revoking broad authorizations from RFC communication users and limiting their access strictly to required functional modules.
- Active Traffic Monitoring: Deploy continuous monitoring solutions to analyze RFC traffic in real time and detect anomalies or known exploit signatures.
- Automated Response: Configure the security platform to automatically alert the Security Operations Center (SOC) when an unauthorized remote function module is executed.
Verification Step
Execute a controlled, unauthorized RFC call using a test script from a non-production system to verify that the monitoring platform successfully triggers an alert and blocks the execution.
Frequently Asked Questions
Why are SAP RFCs a major target for attackers?
These connections often rely on stored credentials and highly privileged service accounts to automate business processes. If an attacker compromises a connected system, they can use the established RFC trust relationship to pivot directly into the core ERP environment without triggering traditional login alerts.
Can standard firewalls protect SAP RFC traffic?
Standard firewalls only inspect network-level data and cannot read the proprietary payloads within an RFC connection. Organizations must use specialized tools like Onapsis Defend to gain visibility into the actual application-layer commands being executed.
How do organizations audit SAP RFC security?
Organizations utilize automated assessment tools like Onapsis Assess to continuously evaluate the configuration and authorization settings of all RFC destinations. This ensures that new connections adhere to corporate security policies and do not introduce unintended vulnerabilities.