RFC SAP Security: How to Protect RFC Connections in the SAP Landscape

Introduction to RFC SAP Security

RFC SAP security is currently one of the most critical aspects in protecting modern SAP infrastructures. RFC Connections enable communication between SAP systems, middleware, and external applications, but an incorrect configuration can turn into a serious cybersecurity risk.

“An insecure RFC can become a lateral movement path within the SAP landscape.”

For BASIS and Security teams, protecting RFC connections means reducing the risk of unauthorized access, privilege escalation, and lateral movement across SAP systems.

In this article we will analyze:

• Trusted RFC
• technical users
• password rotation
• SNC encryption
• lateral risks in the SAP landscape

What are RFC Connections in SAP

RFC (Remote Function Call) allows SAP systems to communicate and execute remote functions across different environments.

RFCs are used for:

• SAP-to-SAP integrations
• connections with external systems
• operational automation
• distributed background jobs
• application data exchange

Connections are usually configured via transaction SM59, becoming a fundamental component of the SAP architecture.

From an RFC SAP security perspective, every RFC connection must be considered a potential attack vector.

RFC SAP Security and Trusted RFC

What are Trusted RFCs

Trusted RFCs allow an SAP system to automatically authenticate to another system without requiring additional passwords during RFC calls.

This approach improves:

• automation
• user experience
• integration between SAP systems

owever, it also introduces significant risks for RFC SAP security.

Risks of Trusted RFCs

If a source system is compromised, an attacker can exploit the trusted relationship to:

• access other SAP systems
• execute privileged RFC calls
• move laterally within the landscape
• extract sensitive data

Trusted RFCs therefore become a potential attack propagation point.

Best practices for Trusted RFCs

Limit trusted relationships

Only configure Trusted RFCs that are truly necessary.

Apply the principle of least privilege

RFC users must have minimal authorizations.

Monitor RFC connections

Perform periodic reviews of configured connections.

Segment the SAP landscape

Separate Development, QA, and Production environments to reduce lateral risks.

Technical users and RFC SAP Security

Perché gli utenti tecnici rappresentano un rischio

Technical users used in RFCs often have elevated privileges and static passwords.

Very often these accounts:

• never expire
• are not monitored
• use shared passwords
• retain excessive authorizations

This scenario significantly increases operational risk.

Common mistakes in RFC user management

Use of SAP_ALL

Assigning SAP_ALL to RFC users is a highly risky practice.

Duplicate passwords

Reusing technical passwords across multiple systems facilitates multiple compromises.

Lack of auditing

Many RFC users are not included in corporate IAM or GRC controls.

Proper management of technical identities is essential to improve RFC SAP security.

Password Rotation in RFC SAP Security

Why password rotation is essential

Static passwords represent one of the main weaknesses of RFC Connections.

A technical account with a password unchanged for years can be easily exploited in case of:

• data leak
• system compromise
• access to logs
• exposure of technical scripts

Best practices for password rotation

Define rotation policies

Establish regular password change cycles.

Automate the process

Use PAM solutions such as:

• CyberArk
• HashiCorp Vault
• SAP Secure Storage

Avoid hardcoded credentials

RFC passwords must not be stored in:

• scripts
• Git repositories
• configuration files
• technical documentation

Test integrations

Every change must be validated to avoid operational disruptions.

SNC Encryption and RFC SAP Security

What is SNC

SNC (Secure Network Communications) is the SAP framework used to protect RFC communications through:

• encryption
• secure authentication
• integrity protection

Why SNC is important

Without SNC, RFC traffic can be intercepted by an attacker present on the network.

Risks include:

• credential theft
• traffic sniffing
• replay attacks
• data manipulation

Benefits of SNC encryption

Communication protection

RFC data is transmitted in encrypted form.

Strong authentication

Supports integration with Kerberos and certificates.

Compliance and audit

Helps meet regulatory requirements and security standards.

For more technical details on SNC, official SAP documentation is available at SAP SNC Documentation

Lateral risks and lateral movement in the SAP landscape

What is lateral movement?

Lateral movement is the ability of an attacker to move from a compromised system to other internal systems.

In the SAP context, this risk is particularly high due to RFC interconnections.

Typical attack scenario

A possible scenario includes:

1. initial compromise of an SAP system
2. access to RFC credentials
3. use of Trusted RFCs
4. privilege escalation
5. propagation toward Production

An effective RFC SAP security strategy must prevent this type of lateral movement.

RFC SAP Security Best Practices

RFC governance

• complete RFC inventory
• defined ownership
• periodic reviews

user security

• elimination of SAP_ALL
• account segregation
• password rotation
• access monitoring

Network security

• SNC mandatory
• network segmentation
• RFC firewall

Monitoring and auditing

• RFC logging
• SIEM integration
• anomaly alerting
• behavioral analysis

RFC SAP security is a fundamental element for protecting the SAP landscape from compromises and lateral attacks.

Trusted RFCs configured without proper controls, over-privileged technical users, and lack of SNC encryption can turn a simple application connection into a serious security risk.

Investire in:

• RFC governance
• password rotation
• SNC encryption
• continuous monitoring

helps drastically reduce the attack surface and improve the overall resilience of the SAP infrastructure.