CVE-2025-42957 Overview
SAP S/4HANA contains a critical code injection vulnerability in a function module exposed via Remote Function Call (RFC). An attacker with basic user privileges can exploit this flaw to inject arbitrary ABAP code into the system, effectively bypassing essential authorization checks. This vulnerability functions as a backdoor, creating the risk of full system compromise and undermining the confidentiality, integrity, and availability of the entire SAP environment.
Critical Impact
This vulnerability enables authenticated attackers to inject arbitrary ABAP code, potentially leading to complete system takeover, data exfiltration, and operational disruption of critical business processes.
Affected Products
- SAP S/4HANA (specific versions affected - refer to SAP Note #3627998)
Discovery Timeline
- August 12, 2025 - CVE-2025-42957 published to NVD
- August 12, 2025 - Last updated in NVD database
Technical Details for CVE-2025-42957
Vulnerability Analysis
This vulnerability is classified as CWE-94 (Improper Control of Generation of Code - Code Injection), representing one of the most severe vulnerability classes in enterprise software. The flaw exists within a function module that is exposed via SAP's Remote Function Call (RFC) interface. RFC is a proprietary SAP protocol that enables communication between SAP systems and external applications, making it a critical attack surface when improperly secured.
The core issue stems from insufficient input validation and authorization checks within the vulnerable function module. When an authenticated user submits specially crafted input through the RFC interface, the system fails to properly sanitize or validate this input before processing it as ABAP code. ABAP (Advanced Business Application Programming) is SAP's proprietary programming language, and the ability to inject arbitrary ABAP code grants attackers the capability to execute virtually any operation within the SAP environment.
The network-accessible nature of this vulnerability, combined with the low complexity required for exploitation and the ability to affect resources beyond the vulnerable component's scope, makes this flaw particularly dangerous. An attacker with only basic user privileges can leverage this vulnerability to escalate privileges, access sensitive business data, modify financial records, or disrupt critical business operations.
Root Cause
The root cause of CVE-2025-42957 is improper input validation and inadequate authorization controls within the affected RFC-enabled function module. The function module fails to properly sanitize user-supplied input before incorporating it into dynamically generated ABAP code. Additionally, the authorization checks that should restrict access to sensitive functionality are either missing or can be bypassed through the injection mechanism.
This represents a classic code injection pattern where user input is treated as code rather than data. The lack of proper input sanitization, combined with the powerful capabilities of ABAP code execution, transforms what should be a controlled data processing function into a dangerous backdoor.
Attack Vector
The attack is executed remotely over the network by an authenticated user with standard SAP user privileges. The attacker connects to the SAP system via RFC and invokes the vulnerable function module with malicious parameters. These parameters contain ABAP code fragments that the system incorrectly processes and executes.
The exploitation process involves:
- Establishing an RFC connection to the target SAP S/4HANA system using valid user credentials
- Identifying and calling the vulnerable function module
- Crafting malicious input containing ABAP code injection payloads
- The system executes the injected code with elevated privileges, bypassing normal authorization checks
- The attacker gains the ability to perform arbitrary operations within the SAP environment
The vulnerability mechanism allows for complete compromise of the SAP system through ABAP code injection. For detailed technical information and remediation guidance, refer to SAP Note #3627998.
Detection Methods for CVE-2025-42957
Indicators of Compromise
- Unusual RFC connection patterns or unexpected function module calls in SAP system logs
- Unexpected ABAP program executions or job scheduling activities from non-administrative users
- Anomalous database queries or data access patterns indicating unauthorized data retrieval
- Creation of new user accounts or modification of authorization roles by non-authorized processes
Detection Strategies
- Monitor SAP Security Audit Log (SM21) for suspicious RFC calls to the affected function module
- Implement SIEM correlation rules to detect unusual patterns of RFC activity combined with sensitive operations
- Review SAP Gateway logs for unexpected external connections and function module invocations
- Deploy SentinelOne Singularity to detect anomalous process behavior and code execution patterns on SAP application servers
Monitoring Recommendations
- Enable comprehensive logging for RFC connections and function module calls in SAP transaction SM21
- Configure real-time alerting for any attempts to execute dynamic ABAP code
- Implement user behavior analytics to identify deviation from normal SAP user activity patterns
- Monitor network traffic for unusual RFC communication patterns using network security monitoring tools
How to Mitigate CVE-2025-42957
Immediate Actions Required
- Apply the security patch referenced in SAP Note #3627998 immediately
- Restrict RFC access to the vulnerable function module using SAP authorization objects
- Review and audit all RFC-enabled function modules for proper authorization controls
- Implement network segmentation to limit RFC access from untrusted network segments
Patch Information
SAP has released a security update addressing this vulnerability. Organizations should apply the patch documented in SAP Note #3627998 as soon as possible. The patch is available through the SAP Security Patch Day portal. Given the critical severity and the potential for complete system compromise, this patch should be prioritized for immediate deployment.
Workarounds
- Disable RFC access to the affected function module using transaction SM59 and SMGW until patching is complete
- Implement additional authorization checks using SAP authorization objects S_RFC and S_PROGRAM
- Configure SAP Gateway security settings to restrict RFC access from external networks
- Enable enhanced logging and monitoring to detect exploitation attempts while awaiting patch deployment
# SAP RFC Security Configuration Example
# Restrict RFC access using gateway security settings (reginfo and secinfo files)
# /usr/sap/<SID>/SYS/global/secinfo
# Deny all RFC access by default, then whitelist trusted hosts
D * * *
P <trusted_host> * <sapgw_service>
# Enable enhanced gateway logging for monitoring
# Set profile parameter gw/logging = X in instance profile
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
