CVE-2016-3976 in Netweaver Java AS
Summary
by MITRE
Directory traversal vulnerability in SAP NetWeaver AS Java 7.1 through 7.5 allows remote attackers to read arbitrary files via a ..\ (dot dot backslash) in the fileName parameter to CrashFileDownloadServlet, aka SAP Security Note 2234971.
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Analysis
by VulDB Data Team • 04/23/2026
The vulnerability identified as CVE-2016-3976 represents a critical directory traversal flaw within SAP NetWeaver Application Server Java version 7.4. This security weakness manifests through the CrashFileDownloadServlet component, which fails to properly validate user-supplied input containing directory traversal sequences. The vulnerability enables remote attackers to access arbitrary files on the affected system by exploiting improper input sanitization mechanisms. Such directory traversal vulnerabilities fall under the broader category of CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental weakness in access control and input validation. The affected SAP NetWeaver AS Java platform serves as a critical enterprise application server infrastructure component, making this vulnerability particularly dangerous for organizations relying on SAP solutions for business-critical operations.
The technical exploitation of this vulnerability occurs when malicious actors send specially crafted requests containing directory traversal sequences such as ../ or ..\ to the CrashFileDownloadServlet endpoint. These sequences allow attackers to navigate beyond the intended directory structure and access files that should remain restricted. The flaw exists because the servlet does not adequately sanitize or validate the input parameters before processing file requests, enabling attackers to manipulate the file path resolution mechanism. This particular vulnerability demonstrates a classic path traversal attack vector that aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: PowerShell, where attackers can leverage such weaknesses to gain unauthorized access to sensitive system information. The vulnerability affects the server-side file access mechanisms and can potentially expose configuration files, source code, database credentials, and other sensitive artifacts that are typically protected within the application's security boundaries.
The operational impact of CVE-2016-3976 extends far beyond simple unauthorized file access, as it can lead to complete system compromise and data exfiltration. Attackers who successfully exploit this vulnerability can potentially access sensitive business data, application source code, configuration files containing database connection strings, and other confidential information that could be used for further attacks. The vulnerability's remote exploitability means that attackers do not need physical access to the network or system, making it particularly dangerous for enterprise environments. Organizations using SAP NetWeaver AS Java 7.4 are at risk of exposure to advanced persistent threats where attackers can use this vulnerability as an initial access vector to establish a foothold within their network infrastructure. This vulnerability directly impacts the confidentiality and integrity of enterprise data, potentially violating compliance requirements and regulatory standards such as those outlined in ISO 27001 and NIST cybersecurity frameworks.
Organizations affected by CVE-2016-3976 should immediately implement comprehensive mitigation strategies to address this vulnerability. The primary remediation involves applying the official SAP security patch referenced in SAP Security Note 2234971, which provides the necessary code modifications to properly validate and sanitize input parameters. Network-level protections should include implementing web application firewalls that can detect and block directory traversal patterns in HTTP requests, as well as restricting access to the CrashFileDownloadServlet endpoint through network segmentation and access control lists. Additionally, organizations should conduct thorough security assessments of their SAP environments to identify and remediate similar vulnerabilities in other components of the application server. The mitigation approach should follow the principle of least privilege, ensuring that the affected servlet and related components operate with minimal required permissions to reduce potential impact if exploitation occurs. Regular security monitoring and log analysis should be implemented to detect suspicious access patterns that might indicate attempted exploitation of this vulnerability.