CVE-2026-0509 in NetWeaver Application Server ABAP and ABAP Platform
Summary
by MITRE • 02/10/2026
SAP NetWeaver Application Server ABAP and ABAP Platform allows an authenticated, low-privileged user to perform background Remote Function Calls without the required S_RFC authorization in certain cases. This can result in a high impact on integrity and availability, and no impact on the confidentiality of the application.
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Analysis
by VulDB Data Team • 02/18/2026
SAP NetWeaver Application Server ABAP and ABAP Platform contains a significant authorization bypass vulnerability that affects authenticated users with low privilege levels. This flaw resides in the background Remote Function Call (RFC) execution mechanism, where the system fails to properly validate authorization requirements before allowing RFC operations to proceed. The vulnerability specifically manifests when certain conditions are met, enabling users who should not have the necessary S_RFC authorization to execute background RFC calls that are typically restricted to higher-privileged accounts. This authorization bypass represents a critical weakness in the system's access control mechanisms and demonstrates a failure in the principle of least privilege enforcement.
The technical implementation of this vulnerability stems from inadequate authorization checking within the RFC processing pipeline. When background RFC calls are initiated through the ABAP platform, the system should verify that the calling user possesses the appropriate S_RFC authorization before proceeding with execution. However, under specific circumstances, this validation process is circumvented, allowing low-privileged users to invoke RFC functions that would normally require elevated permissions. This flaw typically occurs in scenarios involving specific system configurations or when certain middleware components are involved in the RFC processing flow. The vulnerability affects the core ABAP runtime environment and can be exploited through legitimate user accounts that have access to the application server but lack the required administrative privileges.
The operational impact of this vulnerability is severe and multifaceted, primarily affecting system integrity and availability while maintaining confidentiality controls. An attacker with low-privileged access could potentially manipulate backend systems through unauthorized RFC calls, leading to data corruption, system instability, or service disruption. The integrity impact is particularly concerning as background RFC operations can modify system parameters, access sensitive data, or interact with external systems that should be protected from unauthorized access. Availability concerns arise from the potential for disruptive operations that could cause system downtime or resource exhaustion. The absence of confidentiality impact suggests that while the attacker can perform unauthorized operations, they cannot directly access confidential data through this specific vulnerability, though the potential for data manipulation remains significant.
Organizations should implement immediate mitigations including comprehensive authorization reviews and the enforcement of strict access controls for RFC operations. System administrators must ensure that all RFC configurations properly enforce the S_RFC authorization checks and that background RFC execution is restricted to authorized users only. The vulnerability aligns with CWE-284, which addresses improper access control in software systems, and maps to ATT&CK technique T1078 for valid accounts and T1566 for malicious spearphishing. Security teams should conduct thorough audits of all RFC-enabled systems and implement monitoring solutions to detect unauthorized RFC activity. Patch management procedures should be prioritized to address the underlying authorization bypass, and organizations should consider implementing additional security controls such as privileged access management solutions to further reduce the risk of exploitation. Regular security assessments and penetration testing should be conducted to identify similar authorization gaps in the broader SAP ecosystem and ensure comprehensive protection against privilege escalation attacks.