CVE-2019-0327 in NetWeaver for Java Application Server
Summary
by MITRE
SAP NetWeaver for Java Application Server - Web Container, (engineapi, versions 7.1, 7.2, 7.3, 7.31, 7.4 and 7.5), (servercode, versions 7.2, 7.3, 7.31, 7.4, 7.5), allows an attacker to upload files (including script files) without proper file format validation.
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Analysis
by VulDB Data Team • 10/24/2023
SAP NetWeaver for Java Application Server presents a critical security vulnerability in its Web Container component where the engineapi and servercode modules fail to properly validate file upload formats. This flaw exists across multiple versions including 7.1, 7.2, 7.3, 7.31, 7.4, and 7.5, creating a widespread exposure risk for organizations utilizing these platforms. The vulnerability stems from inadequate input validation mechanisms that permit arbitrary file uploads without proper sanitization or format checking, fundamentally undermining the security posture of the application server environment.
The technical implementation of this vulnerability allows attackers to bypass file type restrictions through improper validation logic within the Web Container's upload handling mechanisms. This weakness enables malicious actors to upload script files or executable content that can be executed within the application server context, creating potential attack vectors for code injection and remote command execution. The vulnerability operates at the application layer and specifically targets the file upload functionality, making it particularly dangerous as it can be exploited without requiring elevated privileges or authentication. This flaw aligns with CWE-434 which describes "Unrestricted Upload of File with Dangerous Type" and represents a classic path for privilege escalation and persistent access within target environments.
The operational impact of this vulnerability extends beyond simple file upload capabilities, as it creates opportunities for attackers to establish persistent backdoors, execute malicious code, and potentially compromise the entire application server infrastructure. Organizations running affected SAP NetWeaver versions face significant risk of data breaches, system compromise, and unauthorized access to sensitive business applications. The vulnerability can be exploited through various attack vectors including web application interfaces, API endpoints, or any mechanism that allows file uploads to the server. This represents a critical threat to business continuity and data protection, particularly in environments where SAP NetWeaver serves as a core enterprise application platform.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected SAP NetWeaver versions through official SAP security updates and patches. Organizations must implement robust file validation mechanisms including strict content type checking, filename sanitization, and mandatory file extension filtering to prevent unauthorized uploads. Network segmentation and access controls should be enhanced to limit exposure of vulnerable application components, while monitoring systems should be deployed to detect anomalous file upload activities. The ATT&CK framework categorizes this vulnerability under T1190 "Exploit Public-Facing Application" and T1059 "Command and Scripting Interpreter" as attackers can leverage the upload capability to execute malicious scripts. Additionally, implementing Web Application Firewalls and Content Security Policies can provide additional defense-in-depth measures to protect against exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in the broader SAP ecosystem and ensure comprehensive protection against similar attack vectors.