CVE-2016-7437 in NetWeaver
Summary
by MITRE
SAP Netweaver 7.40 improperly logs (1) DUI and (2) DUJ events in the SAP Security Audit Log as non-critical, which might allow local users to hide rejected attempts to execute RFC function callbacks by leveraging filtering of non-critical events in audit analysis reports, aka SAP Security Note 2252312.
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Analysis
by VulDB Data Team • 09/26/2022
SAP Netweaver 7.40 contains a significant security flaw in its audit logging mechanism that affects the classification and handling of certain security events. The vulnerability specifically impacts the logging of DUI (Data Update Interface) and DUJ (Data Update Job) events within the SAP Security Audit Log system. These events are crucial for monitoring and detecting unauthorized access attempts or malicious activities within SAP environments. The improper logging behavior stems from the system's incorrect categorization of these events as non-critical, which fundamentally undermines the integrity of security monitoring and incident response capabilities.
The technical flaw manifests in how the SAP Security Audit Log processes and classifies security events related to RFC (Remote Function Call) function callbacks. When local users attempt to execute unauthorized RFC function calls, the system should log these as critical security events to ensure proper detection and analysis. However, due to the vulnerability, DUI and DUJ events are being logged with non-critical severity levels, making them susceptible to filtering out during routine audit analysis. This filtering mechanism, which is designed to reduce noise in audit reports by excluding non-critical events, inadvertently creates a security gap that malicious users can exploit to hide their activities.
The operational impact of this vulnerability is substantial for organizations relying on SAP Netweaver 7.40 for their business operations. Local attackers with legitimate access to the system can leverage this flaw to mask unauthorized access attempts and malicious activities by exploiting the audit log filtering mechanism. This creates a false sense of security for system administrators and security teams who rely on audit reports to detect suspicious activities. The vulnerability essentially provides a covert channel for attackers to perform malicious actions without leaving detectable traces in the security audit logs, potentially enabling prolonged unauthorized access to sensitive data and systems.
Organizations affected by this vulnerability should implement immediate mitigations to address the logging inconsistency. The most effective approach involves configuring the SAP Security Audit Log to treat DUI and DUJ events as critical security events regardless of their default classification. This requires modifying the audit log configuration parameters to ensure that all RFC function callback attempts are properly categorized and logged with appropriate severity levels. Additionally, security teams should implement manual verification processes and enhanced monitoring procedures to detect anomalies in system behavior that might indicate exploitation of this vulnerability. The mitigation strategy should also include regular review of audit log configurations to prevent similar issues from arising in future system updates or patches.
This vulnerability aligns with several cybersecurity frameworks and threat modeling concepts. From a CWE perspective, it relates to CWE-693 Protection Mechanism Failure, as the system fails to properly protect against unauthorized access attempts through flawed logging mechanisms. The issue also connects to ATT&CK technique T1070.001 - Indicator Removal on Host, where adversaries remove evidence of their activities by manipulating log files or system configurations. Organizations should consider this vulnerability as part of their broader security posture assessment, particularly in environments where local privilege escalation is a concern and where audit logging is critical for compliance requirements. The security note 2252312 referenced in the vulnerability description provides specific guidance for patching and configuration adjustments that organizations should implement immediately to address this security gap.